Exhibit 99.1

PRESS RELEASE

PACWEST BANCORP ANNOUNCES RESULTS

FOR THE SECOND QUARTER 2017

Highlights

·                  Net Earnings of $93.6 Million, or $0.77 Per Diluted Share

·                  New Loan and Lease Production of $1.1 Billion

·                  Core Deposits Increase of $449 Million and Represent 78% of Total Deposits

·                  Tax Equivalent Net Interest Margin Increased Five Basis Points to 5.21%

·                  Classified Loans and Leases Reduced by 20%

Los Angeles, California . . . PacWest Bancorp (Nasdaq: PACW) today announced net earnings for the second quarter of 2017 of $93.6 million, or $0.77 per diluted share, compared to net earnings for first quarter of 2017 of $78.7 million, or $0.65 per diluted share.  The increase in net earnings from the prior quarter was primarily due to an increase in interest income from higher average balances of interest-earning assets and a lower provision for credit losses.

Matt Wagner, President and CEO, commented, “We delivered outstanding performance in the second quarter and continued to demonstrate our earning power. Our strong second quarter results produced a return on assets of 1.71% and a return on tangible equity of 16.06%. We also continue to proactively

manage credit risk. During the second quarter we sold or contracted to sell loans totaling $221.1 million, including $159.4 million of healthcare cash flow loans. All of these sales have since closed. As a result, our healthcare cash flow loan portfolio today includes only one non-pass rated loan.” Patrick Rusnak, Executive Vice President and CFO stated, “Our second quarter tax equivalent NIM increased five basis points to 5.21%. While the NIM benefitted from the repricing of variable-rate loans, this was partially offset by higher rates on non-core interest-bearing deposits and borrowings.”

Mr. Wagner continued, “We continue to look forward to closing the CU Bancorp acquisition in the fourth quarter of 2017, as we expect regulatory and shareholder approvals to come in the normal course. The date of the CU Bancorp special shareholders meeting has been set and management of both organizations are working on the integration plan.”

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FINANCIAL HIGHLIGHTS

(1) Non-GAAP measure.

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INCOME STATEMENT HIGHLIGHTS

Net Interest Income

Net interest income increased by $10.0 million to $242.5 million in the second quarter of 2017 compared to $232.5 million in the first quarter of 2017 due to higher average yields and balances of loans and leases. The loan and lease yield for the second quarter of 2017 was 6.07% compared to 5.94% for the first quarter of 2017.  The increase in the loan and lease yield was principally due to the higher yields on average loans and leases as a result of the repricing of variable-rate loans due to the increase in market rates during the first half of 2017.

The tax equivalent NIM for the second quarter of 2017 was 5.21% compared to 5.16% for the first quarter of 2017.  The increase in the NIM was mostly due to higher yields on loans and leases due to the upward repricing of variable-rate loans, partially offset by a higher cost of interest-bearing liabilities.

The cost of total deposits increased to 0.25% in the second quarter of 2017 from 0.21% in the first quarter of 2017 due to a higher cost and average balance of non-core deposits.

Noninterest Income

Noninterest income increased by $0.2 million to $35.3 million in the second quarter of 2017 compared to $35.1 million in the first quarter of 2017 due mainly to a $2.2 million increase in leased equipment income due to higher gains on early lease terminations, a $1.8 million increase in gain on sale of securities, and a $0.7 million increase in warrant income, offset by a $4.5 million decrease in other income attributable mainly to a $5.0 million legal settlement with a former borrower recorded in the first quarter of 2017.

The following table presents details of noninterest income for the periods indicated:

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Noninterest Expense

Noninterest expense increased by $1.2 million to $117.7 million in the second quarter of 2017 compared to $116.5 million in the first quarter of 2017 due mostly to a $1.2 million increase in acquisition, integration, and reorganization costs and a $1.1 million charge related to the sale of the unfunded commitments portion of the healthcare loan sale.

The following table presents details of noninterest expense for the periods indicated:

Income Taxes

The overall effective income tax rate was 37.0% in the second quarter of 2017 and 37.7% in the first quarter of 2017.  The estimated effective tax rate for the full year 2017 is approximately 38%.

BALANCE SHEET HIGHLIGHTS

Loans and Leases

Total loans and leases held for investment decreased by $13.2 million in the second quarter to $15.5 billion at June 30, 2017.  The net decrease was driven by principal repayments of $843.1 million, an increase in loans held for sale of $175.2 million, and loan sales of $46.0 million, partially offset by second quarter new production of $1.1 billion. In the second quarter, we sold $46.0 million of loans consisting primarily of loans from our healthcare portfolios. Additionally, we entered into two agreements to sell loans with balances totaling $175.2 million and the associated unfunded commitments of $19.3 million, primarily from our healthcare portfolios.  The $175.2 million of loans were reported as held for sale at June 30, 2017 and the sales were completed in July. As a result of the second quarter loan sales and transfers to loans held for sale, our healthcare cash flow portfolio held for investment decreased from $740.6 million at March 31, 2017 to $514.7 million, including one non-pass rated credit of $19.2 million, at June 30, 2017.

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The following table presents a roll forward of loans and leases held for investment for the periods indicated:

(1) Includes direct financing leases but excludes equipment leased to others under operating leases.

(2) Includes principal disbursements/repayments on existing loans, changes in revolving lines of credit (repayments and draws), loan participation sales and other changes within the loan portfolio.

The following table presents the composition of loans and leases held for investment as of the dates indicated:

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Deposits and Client Investment Funds

The following table presents the composition of our deposit portfolio as of the dates indicated:

At June 30, 2017, core deposits totaled $13.2 billion, or 78% of total deposits, including $6.7 billion of noninterest-bearing demand deposits, or 40% of total deposits.

In addition to deposit products, we also offer alternative non-depository cash investment options for select clients; these alternatives include investments managed by Square 1 Asset Management, Inc. (“S1AM”), our registered investment advisor subsidiary, and third-party sweep products.  Total off-balance sheet client investment funds at June 30, 2017 were $1.8 billion, of which $1.6 billion was managed by S1AM.

PROVISION AND ALLOWANCE FOR CREDIT LOSSES

A provision for credit losses of $11.5 million was recorded in the second quarter of 2017 compared to $24.7 million in the first quarter of 2017. The second quarter provision consisted of $12.5 million for non-purchased credit impaired (“Non-PCI”) loans and leases and a $1.0 negative provision for PCI loans; this compares to provisions of $24.5 million and $0.2 million, respectively, for the first quarter of 2017.  The lower provision for the second quarter of 2017 was mainly attributable to lower general reserves being required because of the decreased levels of classified loans and healthcare cash flow loans, both of which carry greater than average general reserve levels due to charge-off experience.  In addition, the prior quarter provision was higher due to general provisions from increased general reserve loss factors which were influenced by net charge-off experience. The allowance for Non-PCI credit losses to Non-PCI loans and leases held for investment coverage ratio was 1.02% and 1.08% at June 30, 2017 and March 31, 2017.

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The following tables show roll forwards of the allowance for credit losses for the periods indicated:

The gross charge-offs for the second quarter of 2017 included approximately $10.9 million for venture capital loans and $7.2 million related to the recording of the healthcare portfolio loans at the lower of cost or market value at the time of transfer to loans held for sale. The transfer of loans to held for sale also decreased reported nonaccrual loans by $5.3 million and classified loans by $44.8 million. The annualized ratio of net charge-offs to total average loans for the quarter ended June 30, 2017 was 0.54%.

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CREDIT QUALITY

The following table presents Non-PCI loan and lease credit quality metrics as of the dates indicated:

(1) Includes loans and leases held for investment; excludes loans held for sale carried at lower of cost or fair value.

The following table presents Non-PCI nonaccrual loans and leases and accruing loans and leases past due between 30 and 89 days by portfolio segment and class as of the dates indicated:

(1) Includes loans and leases held for investment; excludes loans held for sale carried at lower of cost or fair value.

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The following table presents nonperforming assets as of the dates indicated:

(1) Includes loans and leases held for investment; excludes loans held for sale carried at lower of cost or fair value.

CU BANCORP MERGER ANNOUNCEMENT

On April 6, 2017, PacWest announced the signing of a definitive agreement and plan of merger (the “Agreement”) whereby PacWest will acquire CU Bancorp in a transaction valued at approximately $705 million.

CU Bancorp, headquartered in Los Angeles, California, is the parent of California United Bank, a California state-chartered non-member bank, with approximately $3.1 billion in assets and nine branches located in Los Angeles, Orange, Ventura, and San Bernardino counties at March 31, 2017. In connection with the transaction, California United Bank will be merged into Pacific Western Bank, the principal operating subsidiary of PacWest Bancorp.

The transaction, which was approved by the PacWest and CU Bancorp boards of directors, is expected to close in the fourth quarter of 2017 and is subject to customary closing conditions, including obtaining approval by CU Bancorp’s shareholders and bank regulatory authorities.

ABOUT PACWEST BANCORP

PacWest Bancorp (“PacWest”) is a bank holding company with over $22 billion in assets with one wholly-owned banking subsidiary, Pacific Western Bank (the “Bank”). The Bank has 74 full-service branches located throughout the state of California and one branch in Durham, North Carolina. We provide commercial banking services, including real estate, construction, and commercial loans, and comprehensive deposit and treasury management services to small and medium-sized businesses.  We offer additional products and services through our CapitalSource and Square 1 Bank divisions. Our CapitalSource Division provides cash flow, asset-based, equipment and real estate loans and treasury management services to established middle market businesses on a national basis.  Our Square 1 Bank Division offers a comprehensive suite of financial services focused on entrepreneurial businesses and their venture capital and private equity investors, with offices located in key innovation hubs across the United States.  For more information about PacWest Bancorp, visit www.pacwestbancorp.com, or to learn more about Pacific Western Bank, visit www.pacificwesternbank.com.

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FORWARD LOOKING STATEMENTS

This release contains certain “forward-looking statements” about the Company and its subsidiaries within the meaning of the Private Securities Litigation Reform Act of 1995, including forward-looking statements relating to the Company’s current business plans and expectations regarding future operating results and metrics and including statements about our expectations regarding our pending merger between the Company and CU Bancorp. All statements contained in this release that are not clearly historical in nature are forward-looking, and the words “anticipate,” “assume,” “intend,” “believe,” “forecast,” “expect,” “estimate,” “plan,” “continue,” “will,” “should,” “look forward” and similar expressions are generally intended to identify forward-looking statements. All forward-looking statements (including statements regarding future financial and operating results and future transactions and their results) involve risks, uncertainties and contingencies, many of which are beyond our control, which may cause actual results, performance, or achievements to differ materially from anticipated results, performance or achievements. These risks and uncertainties include, but are not limited to, our ability to compete effectively against other financial institutions in our banking markets; the impact of changes in interest rates or levels of market activity, especially on our loan and investment portfolios; deterioration, weaker than expected improvement, or other changes in the state of the economy or the markets in which we conduct business (including the levels of IPOs and M&A activities); changes in credit quality and the effect of credit quality on our provision for loan and lease losses and allowance for loan and leases losses; our ability to attract deposits and other sources of funding or liquidity; our capital requirements and our ability to generate capital internally or raise capital on favorable terms; the costs and effects of legal, compliance and regulatory actions, changes and developments, including the impact of adverse judgments or settlements in litigation, the initiation and resolution of regulatory or other governmental inquiries or investigations, and/or the results of regulatory examinations or reviews; the Company’s ability to complete the proposed CU Bancorp transaction, including by obtaining regulatory approvals and approval by the shareholders of CU Bancorp, or any future transaction, successfully integrate such acquired entities, or achieve expected beneficial synergies and/or operating efficiencies, in each case within expected timeframes or at all; changes in the Company’s stock price before completion of the CU Bancorp merger, including as a result of the financial performance of the Company or CU Bancorp before closing; and our success at managing the risks involved in the foregoing items and all other factors set forth in the Company’s public reports, including the Annual Report on Form 10-K for the year ended December 31, 2016, and particularly the discussion of risk factors within that document.

All forward-looking statements included in this release are based on information available at the time of the release. We are under no obligation to (and expressly disclaim any such obligation to) update or alter our forward-looking statements, whether as a result of new information, future events or otherwise except as required by law.

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ADDITIONAL INFORMATION ABOUT THE PROPOSED TRANSACTION AND WHERE TO FIND IT

Investors and security holders are urged to carefully review and consider each of PacWest’s and CU Bancorp’s public filings with the SEC, including but not limited to their Annual Reports on Form 10-K, their proxy statements, their Current Reports on Form 8-K and their Quarterly Reports on Form 10-Q. The documents filed by PacWest with the SEC may be obtained free of charge at PacWest’s website at www.pacwestbancorp.com or at the SEC’s website at www.sec.gov. These documents may also be obtained free of charge from PacWest by requesting them in writing to PacWest Bancorp, 9701 Wilshire Boulevard, Suite 700, Beverly Hills, CA 90212; Attention: Investor Relations, by submitting an email request to investor-relations@pacwestbancorp.com or by telephone at (310) 887-8521.

The documents filed by CU Bancorp with the SEC may be obtained free of charge at CU Bancorp’s website at www.cubancorp.com or at the SEC’s website at www.sec.gov. These documents may also be obtained free of charge from CU Bancorp by requesting them in writing to CU Bancorp, 818 W. 7th Street, Suite 220, Los Angeles, CA 90017; Attention: Investor Relations, or by telephone at 818-257-7700.

PacWest has filed a registration statement with the SEC which includes a proxy statement of CU Bancorp and a prospectus of PacWest, and each party will file other documents regarding the proposed transaction with the SEC. Before making any voting or investment decision, investors and security holders of CU Bancorp are urged to carefully read the entire registration statement and proxy statement/prospectus, as well as any amendments or supplements to these documents, because they will contain important information about the proposed transaction. A definitive proxy statement/prospectus will be sent to the shareholders of CU Bancorp seeking any required shareholder approvals. Investors and security holders are able to obtain the registration statement and the proxy statement/prospectus free of charge from the SEC’s website or from PacWest or CU Bancorp by writing to the addresses provided for each company set forth in the paragraphs above.

PacWest, CU Bancorp, their directors, executive officers and certain other persons may be deemed to be participants in the solicitation of proxies from CU Bancorp shareholders in favor of the approval of the transaction. Information about the directors and executive officers of PacWest and their ownership of PacWest common stock is set forth in the proxy statement for PacWest’s 2017 annual meeting of stockholders, as previously filed with the SEC. Information about the directors and executive officers of CU Bancorp and their ownership of CU Bancorp common shares is set forth in the proxy statement for CU Bancorp’s 2016 annual meeting of shareholders, as previously filed with the SEC. Shareholders may obtain additional information regarding the interests of such participants by reading the registration statement and the proxy statement/prospectus.

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PACWEST BANCORP AND SUBSIDIARIES

CONDENSED CONSOLIDATED BALANCE SHEET

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PACWEST BANCORP AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENT OF EARNINGS