The first of four men accused in a failed plan to build a biotechnology plant in Vermont using tens of millions of dollars in foreign investors’ money raised through a special visa program was sentenced Thursday to 18 months in prison. William Stenger, 73, the former president of the Jay Peak ski resort, also was sentenced to three years of supervisory release and ordered to pay $250,000 in restitution. He pleaded guilty last August to providing false documents. In exchange, nine fraud charges were dropped. Stenger told the court he wished to apologize to his family, the employees of Jay Peak and Burke ski resorts, the state, the investors, and his community of Newport. “I let you down,” he said, adding that he started out with the best intentions and “got lost along the way.” Defense lawyers tried to pin the blame on the state, saying regulators suspected that there were financial troubles, but lifted a state imposed freeze on fundraising from additional investors. Former Department of Financial Regulation Commissioner Susan Donegan said Thursday a financial review was underway and it would have been premature to not allow the project to go forward. She said she was not pressured by then-Gov. Peter Shumlin to lift the hold on fundraising, but that he wanted the project to move forward. Federal prosecutors requested a five-year sentence for Stenger, the maximum under the plea deal, while Stenger’s lawyers asked for home confinement.