Sen. Ted Stevens (R-Alaska) was indicted by a federal grand jury Tuesday on seven felony counts for concealing more than $250,000 in gifts from an oil services company.

The news that the longest-serving Republican senator in history faced charges from an investigation into his relationship with the VECO Corp. roiled Capitol Hill, sent the Senate Republican Conference into damage control, and cast serious doubt that Stevens would be able to win a seventh full term this fall.

Stevens, 84, was chairman of the Senate Appropriations Committee from 1997 until 2005, except for an 18-month period in 2001 and 2002 when Democrats controlled the chamber.

The VECO investigation has already produced convictions of Alaska lawmakers, oil executives and a lobbyist. The FBI and IRS raided Stevens’s home in 2007.

Stevens released a statement saying he never “knowingly submitted a false disclosure form required by law as a U.S. senator.”

“The impact of these charges on my family disturbs me greatly,” Stevens said in the statement. “I am innocent of these charges and intend to prove that.”

Justice officials said Stevens would not be arrested, instead allowing him to turn himself in. Stevens’s lawyer received a call from Justice officials Tuesday morning saying that an indictment had been agreed upon by a federal grand jury in Washington.

Stevens said in his statement that he has temporarily resigned his vice chairmanship of the GOP Senate conference as well as his ranking positions on the Commerce, Science and Transportation Committee and the powerful Appropriations Defense subcommittee.

VECO is Stevens’s second-biggest campaign contributor, according to the Center for Responsive Politics, giving him roughly $88,000.

Stevens could face up to 35 years in prison, with each count of making a false statement bringing up to five years of jail time. It is highly unlikely Stevens will face the maximum penalty if convicted.