The General Electric [GE]-Rolls-Royce partnership developing the second F-35 Joint Strike Fighter engine said Friday they will abandon the project at the end of the year.

“The GE Rolls-Royce Fighter Engine Team (FET) has reached the decision to discontinue self-funded development of the F136 engine for the Joint Strike Fighter (JSF) beyond 2011,” the companies said in a joint statement.

The Pentagon terminated the alternative F-136 engine in April and showed little enthusiasm for the contracting team’s willingness to fund the program themselves to keep it alive.

"GE and Rolls-Royce are proud of our technology advancements and accomplishments on the F136," Dan McCormick, the president of the industry team, said. "However, difficult circumstances are converging that impact the potential benefit of a self-funded development effort."

GE and Rolls-Royce said the decision recognized “the continued uncertainty in the development and production schedules for the JSF program.”

The JSF program has been plagued by cost overruns and delays and has faced renewed scrutiny on Capitol Hill at time of budget constraints.

Pentagon spokesman George Little said Friday officials had continued to discuss the second engine with GE and Rolls-Royce but the decision to drop the self-funding proposal was at the discretion of the two companies.

“This was a decision, as I understand it, that was made by GE and Rolls-Royce at the end of the day,” he said.

The Pentagon has maintained the second engine program is unneeded and too expensive, and axed it after Congress voted to kill funding for it in fiscal 2011 legislation. The White House had strongly opposed the second engine and threatened to veto any bill seeking to fund it.

Pratt & Whitney [UTX] builds the F135 engine that is powering the Lockheed Martin [LMT]-built JSF. The F135 has been hit with cost overruns, which partly fueled interest in keeping the program alive.

GE and Rolls-Royce representatives were to have met with senior Pentagon officials a couple months ago to pitch the self-funding proposal. But before the meeting, Deputy Defense Secretary Ashton Carter, then acquisition chief, said he had “real concerns” about the proposal.

GE and Rolls-Royce had been bolstered my numerous prominent lawmakers who supported the second engine but were unable to get it funded.

Rep. Howard “Buck” McKeon (R-Calif.)  said in a statement Friday he was “disappointed” GE and Rolls-Royce were forced to cancel the initiative and that the second engine could have been a model for competitive acquisition.

“This development is a blow to common-sense acquisition reform at the Department of Defense,” McKeon, the chairman of the House Armed Services Committee, said.

The House version of the defense authorization bill passed in May offered no money for the alternative engine, but expressed support for the self-funding proposal. The Senate version passed Thursday night did not contain similar language.

The Pentagon had been trying to kill the F136 since 2006, only to see Congress restore the funding then and in subsequent years.

The GE-Rolls Royce statement said the F136 was nearly 80 percent complete when it was canceled, and that six of the engines had logged more than 1,200 hours of testing since early 2009. The companies said their engine demonstrated a significant thrust margin for lower operating temperatures than the Pratt & Whitney version.