Solyndra’s two top executives plan to invoke their Fifth Amendment rights and refuse to answer questions when they testify Friday before a House Energy and Commerce Committee panel investigating the failed solar panel maker, which received more than $500 million in federally backed loans.

But in a statement, the company asserted that it “is not aware of any wrongdoing by Solyndra officers, directors or employees in conjunction with the [Energy Department] loan guarantee.” Solyndra said it is cooperating fully with a criminal investigation by the U.S. Attorney for the northern district of California.

The Solyndra executives had been asked to testify last week but delayed their appearance, saying they would cooperate this week and promising not to invoke their rights to avoid self-incrimination.

Attorneys for Solyndra chief executive Brian Harrison and chief financial officer W.G. “Bill” Stover said Tuesday that they advised their clients not to answer questions from House lawmakers. They cited the Justice Department investigation and the FBI’s recent raid of Solyndra’s Fremont, Calif., offices.

“This is not a decision arrived at lightly,” Harrison’s attorney, Walter F. Brown, said in a letter obtained by The Washington Post, “but it is a decision dictated by current circumstances.”

Stover’s attorney, Jan Nielsen Little, said in another letter that “nothing of substance should be read into Mr. Stover’s decision to heed his counsel’s advice and assert his Fifth Amendment rights.”

Committee Republicans blasted the executives for reneging on their written promise not to take the Fifth Amendment if testimony was delayed. They said they plan to swear in the executives nonetheless and urge them to reconsider.

“Who exactly are Solyndra’s executives trying to protect and what are they trying to hide?” asked a statement released by the committee’s chairman, Fred Upton (R-Mich.), and the investigations subcommittee’s chairman, Cliff Stearns (R-Fla.).

“It’s disappointing that the officials who canvassed the halls of Congress in mid-July and misled our members about the financial state of their company are now unwilling to answer direct questions, but any effort to cover up the truth will ultimately not succeed,” they said. In a separate move, Upton and two other panel members said they would seek information on the financial conditions of 14 projects to which the Energy Department is poised to award loans.

The GOP lawmakers said they were concerned that the Energy Department might be “rushing” to award $9 billion in loan guarantees before the program expires at the end of the month.

Also on Tuesday, Rep. Darrell Issa (R-Calif.) said in a cable TV interview that the House Oversight and Government Reform Committee, which he heads, will investigate Solyndra and federal loan guarantees.

Staff writer Carol D. Leonnig contributed to this report.