By Yereth Rosen

ANCHORAGE, Alaska (Reuters) - Two former state legislators were spared further prison time on Friday after pleading guilty to charges stemming from a longstanding federal investigation into political corruption in Alaska.

Former state Representative Vic Kohring pleaded guilty to one charge of conspiracy to commit bribery for federal government programs and former state House Speaker Pete Kott pleaded guilty to one bribery count in separate proceedings.

"I think we need finality," U.S. District Court Judge Ralph Beistline said when sentencing Kott. "I recognize the need to put this long state nightmare to an end."

The pleas closed a five-year-old federal probe that targeted VECO Corp, then Alaska's largest oil-services company, the late U.S. Senator Ted Stevens and several other Alaska politicians and prominent businessmen.

Beistline called the scandal a "dark moment" in Alaska political history.

U.S. Attorney for the District of Alaska, Karen Loeffler, said the case is now closed, bringing an end to the biggest corruption investigation in all of Alaska history.

Stevens, the Senate's longest-serving Republican, was convicted in 2008 of concealing some $250,000 worth of gifts from VECO and lost the seat he held for 40 years.

Stevens' conviction was overturned in April of 2009, and the indictment against him dismissed based on what a federal judge ruled egregious prosecutorial misconduct. He died in a plane crash in August of 2010.

VECO, for years one of Alaska's most powerful and politically connected corporations, disappeared as a separate entity, its assets purchased by a rival company.

Former Wasilla Mayor Sarah Palin used the scandal to wage a successful 2006 gubernatorial campaign as an anti-corruption outsider.

Both men were freed after the judge accepted their plea agreements based on time already served in prison -- 17 months in Kott's case and 12 months in Kohring's case.

Kott will be on probation for up to three years, and was ordered to pay a $10,000 fine. Kohring, who was given up to 18 months probation, was exempted from such a fine due to financial hardship.

The two Republicans were convicted in separate 2007 trials, but an appeals court threw out those convictions. The plea deals eliminate the need for retrials.

(Editing by Mary Slosson and David Bailey)