Exhibit 99.1

FOR IMMEDIATE RELEASE

Willbros Reports Fourth Quarter and Full Year 2013 Results from Continuing Operations

HOUSTON, TX, FEBRUARY 27, 2014 — Willbros Group, Inc. (NYSE: WG) announced today results from continuing operations for the fourth quarter and full year 2013. The Company reported a net loss from continuing operations in the fourth quarter of $348 thousand, or $0.00 per share, on revenue of $540.5 million. In the fourth quarter of 2013, operating income increased to $15.5 million compared to operating income of $5.7 million in the fourth quarter of 2012 on revenue of $556.7 million. The results for 2012 included a non-cash, pre-tax goodwill impairment charge of $8.1 million related to the Utility T&D segment.

2013 Accomplishments:

“We continue to make meaningful progress toward accomplishing the strategic objectives we established at the beginning of 2013,” commented Randy Harl, President and Chief Executive Officer. “When we last reported, we stated that we expected that all four segments would be profitable at the operating level in the fourth quarter of 2013. I am pleased to report we met that expectation. We delivered another sequential improvement with operating income of $15.5 million. Canada delivered strong performance in 2013 and produced operating margins of 7.9 percent for the year.

“In the Oil & Gas segment, operations improved and we have addressed the issues that led to the losses generated by our regional delivery services. Our actions are proving successful, with three consecutive quarter-on-quarter improvements. We have also established clear performance standards and an assurance process to verify that these standards are being met.”

For the full year 2013, the Company reported a net loss from continuing operations attributable to Willbros Group, Inc. of $23.4 million, or $0.48 per share, on revenue of $2.0 billion compared to a net loss of $23.3 million, or $0.49 per share, on revenue of $1.9 billion in 2012. Fiscal 2013 results included a debt extinguishment charge of $11.6 million, or $0.24 per share, associated with the refinancing of its previous credit facility. Operating income for the full year 2013 was $34.1 million compared to operating income of $14.8 million in 2012, which included a non-cash, pre-tax goodwill impairment charge of $8.1 million.

		Michael W. Collier Vice President Investor Relations Sales & Marketing Willbros 713-403-8038		1 of 4 CONTACT: Connie Dever Director Investor Relations Willbros 713-403-8035

Backlog⁽³⁾

At December 31, 2013, Willbros reported total backlog from continuing operations of $2.0 billion compared to $2.1 billion at December 31, 2012. Twelve month backlog of $1.1 billion at the end of 2013 increased $129 million from September 30, 2013 and $75 million over the fourth quarter of 2012; largely driven by two significant cross-country pipeline project awards. Subsequent to December 31, 2013, the Company was awarded three mid-sized pipeline projects in the Oil & Gas segment.

Segment Operating Results

Oil & Gas

For the fourth quarter of 2013, the Oil & Gas segment generated revenue of $235.5 million and operating income of $1.9 million, a $10.7 million sequential improvement and a $1.6 million improvement in operating income from the fourth quarter of 2012. The fourth quarter results were driven by the contribution of a major pipeline project that was 66 percent complete at December 31 and by improved performance in its regional services. The segment reported an operating loss of $40.2 million for the full year on revenue of $791.1 million, primarily a result of losses in the regional service lines in the first half of the year.

Utility T&D

For the fourth quarter of 2013, the Utility T&D segment reported operating income of $2.8 million on revenue of $96.6 million compared to operating income of $2.9 million on revenue of $108.1 million in the third quarter and an operating loss of $2.9 million on revenue of $121.7 million in the fourth quarter of 2012 which included a non-cash, after-tax goodwill impairment charge of $8.1 million. Results for the fourth quarter of 2013 reflect the impact of adverse weather which caused delays and lower productivity in both our transmission and distribution services. For the full year, operating income increased $18.3 million while revenue decreased $37.4 million over 2012. The reduction in revenue was related to the adverse weather in November and December and completion of the Oncor Texas CREZ projects.

Canada

For the fourth quarter of 2013, Canada’s operating income increased $3.6 million, or 61 percent, to $9.5 million as a result of increased margins on higher revenue compared to the fourth quarter of 2012. For the full year, the segment generated operating income of $35.4 million on revenue of $445.2 million compared to a small operating loss in 2012. The improvement in operating income compared to last year was attributable to revenue gains from increased market penetration, quality backlog and safe, reliable execution of core construction and maintenance services performed for key customers. Contract revenue increased $228.4 million over 2012 firmly demonstrating that the segment is ahead of schedule to achieve its previously established growth target.

		Michael W. Collier Vice President Investor Relations Sales & Marketing Willbros 713-403-8038		2 of 4 CONTACT: Connie Dever Director Investor Relations Willbros 713-403-8035

Professional Services

The Professional Services segment reported operating income of $1.3 million on revenue of $89.8 million in the fourth quarter compared to operating income of $2.3 million on revenue of $82.3 million in the fourth quarter of 2012. The decrease in the fourth quarter operating income reflects reduced storm restoration work compared to 2012. For the full year, operating income increased 38 percent over 2012 to $15.7 million and revenue increased 4 percent to $342.7 million.

Outlook

Willbros believes that the markets it serves remain strong. With the recent backlog additions in the Oil & Gas segment, the Company has good visibility with regard to its large-diameter pipeline spread capacity that is largely booked into early fall of this year. The Company’s focus on growing midstream pipeline and facilities and pipeline integrity opportunities is expected to result in significantly improved performance in its regional delivery services this year. The Utility T&D segment is transitioning in 2014 to address the opportunity to perform electric transmission and distribution work for new customers, particularly in the markets contiguous to our strong presence in Texas. The Canada segment is very well positioned to continue its strong performance and the Company will continue to expand its service offerings in Northern Alberta. The Professional Services segment has upside potential for operating margin improvement as the Company benefits from the investments it made to expand its geographic presence and services in 2013.

Liquidity

At December 31, 2013, the Company had $42.6 million of cash and cash equivalents. Outstanding revolver borrowings were $19.0 million, with $60.1 million in letters of credit outstanding, resulting in $70.9 million remaining against the approximately $150.0 million of borrowing base availability. Subsequent to December 31, 2013, the Company paid the outstanding revolver borrowings in full through proceeds received in connection with the sale of Hawkeye and through cash flow from operations. The Company expects to continue strengthening its balance sheet through improved cash flow from operations and potential sales of non-strategic and under-performing assets (including equipment, real property and businesses).

Guidance

Van Welch, Willbros Chief Financial Officer, commented, “We expect annual revenue to range from $2.1 to $2.3 billion in 2014. We expect our operating results to improve significantly in 2014 with an increase every quarter in 2014 as compared to the corresponding quarter in 2013. We expect first quarter operating results to be down from the fourth quarter of 2013 due to inclement weather and the transition underway of our Utility T&D segment.

“We expect to reduce our Term Loan debt by approximately $30 to $50 million and fund the final payments due under the WAPCo settlement by the end of the year through cash flow from operations and proceeds from potential asset sales.”

		Michael W. Collier Vice President Investor Relations Sales & Marketing Willbros 713-403-8038		3 of 4 CONTACT: Connie Dever Director Investor Relations Willbros 713-403-8035

Conference Call

In conjunction with this release, Willbros has scheduled a conference call, which will be broadcast live over the Internet, on Friday, February 28, 2014 at 9:00 a.m. Eastern Time (8:00 a.m. Central).

For those who cannot listen to the live call, a replay will be available through March 7, 2014 and may be accessed by calling 303-590-3030 or 800-406-7325 using pass code 4669451 #. Also, an archive of the webcast will be available shortly after the call on www.willbros.com.

Willbros Group, Inc. is an independent contractor serving the oil, gas, power, refining and petrochemical industries, providing engineering, construction, turnaround, maintenance, life-cycle extension services and facilities development and operations services to industry and government entities worldwide. For more information on Willbros, please visit our web site at www.willbros.com.

This announcement contains forward-looking statements. All statements, other than statements of historical facts, which address activities, events or developments the Company expects or anticipates will or may occur in the future, are forward-looking statements. A number of risks and uncertainties could cause actual results to differ materially from these statements, including new legislation or regulations detrimental to the economic operation of refining capacity in the United States; the identification of one or more other issues that require restatement of one or more prior period financial statements; contract and billing disputes; the consequences the Company may encounter if it is unable to make payments required of it pursuant to its settlement agreement of the West African Gas Pipeline Company Limited lawsuit; the existence of material weaknesses in internal control over financial reporting; availability of quality management; availability and terms of capital; changes in, or the failure to comply with, government regulations; ability to remain in compliance with, or obtain waivers under, the Company’s existing loan agreements; the promulgation, application, and interpretation of environmental laws and regulations; future E&P capital expenditures; oil, gas, gas liquids, and power prices and demand; the amount and location of planned pipelines; poor refinery crack spreads; delay of planned refinery outages and upgrades and development trends of the oil, gas, power, refining and petrochemical industries; as well as other risk factors described from time to time in the Company’s documents and reports filed with the SEC. The Company assumes no obligation to update publicly such forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required by law.

TABLE TO FOLLOW

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		Michael W. Collier Vice President Investor Relations Sales & Marketing Willbros 713-403-8038		4 of 4 CONTACT: Connie Dever Director Investor Relations Willbros 713-403-8035

WILLBROS GROUP, INC.

(In thousands, except per share amounts)