Exhibit 99.1

PennyMac Mortgage Investment Trust Declares Fourth Quarter 2010 Dividend

Calabasas, CA December 28, 2010 — The Board of Trustees of PennyMac Mortgage Investment Trust (NYSE: PMT) declared a cash dividend of $0.42 per common share of beneficial interest for the fourth quarter of 2010.  This dividend is payable January 28, 2011 to common shareholders of record on January 12, 2011.

About PennyMac Mortgage Investment Trust

PennyMac Mortgage Investment Trust is a mortgage real estate investment trust (REIT) that invests primarily in residential mortgage loans and mortgage-related assets.  PennyMac Mortgage Investment Trust trades on the New York Stock Exchange under the symbol “PMT” and is externally managed by PNMAC Capital Management, LLC, a wholly owned subsidiary of Private National Mortgage Acceptance Company, LLC. Additional information about PennyMac Mortgage Investment Trust is available at www.pennymacmortgageinvestmenttrust.com.

This press release contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended, regarding management’s beliefs, estimates, projections and assumptions with respect to, among other things, the Company’s financial results, future operations, business plans and investment strategies, as well as industry and market conditions, all of which are subject to change.  Words like “believe,” “expect,” “anticipate,” “promise,” “plan,” and other expressions or words of similar meanings, as well as future or conditional verbs such as “will,” “would,” “should,” “could,” or “may” are generally intended to identify forward-looking statements.  Actual results and operations for any future period may vary materially from those projected herein and from past results discussed herein.  Factors which could cause actual results to differ materially from historical results or those anticipated include, but are not limited to:  changes in general business, economic, market and employment conditions from those expected; continued declines in residential real estate and disruption in the U.S. housing market; the availability of, and level of competition for, attractive risk-adjusted

investment opportunities in residential mortgage loans and mortgage-related assets that satisfy our investment objectives and investment strategies; changes in our investment or operational objectives and strategies, including any new lines of business; the concentration of credit risks to which we are exposed; the availability, terms and deployment of short-term and long-term capital; unanticipated increases in financing and other costs, including a rise in interest rates; the performance, financial condition and liquidity of borrowers; increased rates of delinquency or decreased recovery rates on our investments; increased prepayments of the mortgage and other loans underlying our investments; changes in regulations or the occurrence of other events that impact the business, operation or prospects of government sponsored enterprises; changes in government support of homeownership; changes in governmental regulations, accounting treatment, tax rates and similar matters; and our ability to satisfy complex rules in order to qualify as a REIT for U.S. federal income tax purposes.  You should not place undue reliance on any forward-looking statement and should consider all of the uncertainties and risks described above, as well as those more fully discussed in reports and other documents filed by the Company with the Securities and Exchange Commission from time to time.  The Company undertakes no obligation to publicly update or revise any forward-looking statements or any other information contained herein, and the statements made in this press release are current as of the date of this release only.