By Nate Raymond

BOSTON (Reuters) -A Russian-born founder of a cryptocurrency financial services firm avoided having to spend any further time in a U.S. prison on Thursday for participating in a wide-ranging scheme to manipulate the market for digital tokens on behalf of his company's clients.

Federal prosecutors in Boston had argued that Aleksei Andriunin, the founder and CEO of cryptocurrency "market maker" Gotbit, deserved a 15-month prison sentence after he pleaded guilty in March to charges that he conspired to commit market manipulation and engaged in wire fraud.

Instead, U.S. District Judge Angel Kelley sentenced him to just eight months in prison, which he was deemed to have already served based on the time he spent in jail following his arrest in October in Portugal, prosecutors said. Portugal extradited him in February.

He now faces deportation. His company Gotbit was meanwhile ordered to forfeit $23 million worth of cryptocurrency as part of a separate plea deal.

"We're incredibly gratified by the sentence, and he's looking forward to getting home to his wife and family," Roger Burlingame, his lawyer at Dechert, said.

Andriunin and Gotbit were among 15 people and three firms charged last year following a novel investigation dubbed "Operation Token Mirrors," in which the FBI for the first time directed the creation of its own digital token to help catch fraudsters in the crypto market.

Before the charges were filed, Gotbit was a premier "market maker" in the cryptocurrency industry, making tens of millions of dollars in annual revenue and employing over 200 people, prosecutors said.

Prosecutors said that from 2018 to 2024, Gotbit engaged in "wash trading," a form of sham trading, and market manipulation on behalf of several cryptocurrency clients to help artificially inflate trading volume for their tokens.

Prosecutors cited a 2019 interview published online in which Andriunin described developing a code to wash trade cryptocurrencies to artificially inflate trading volume so they could become listed on larger cryptocurrency exchanges.

(Reporting by Nate Raymond in Boston; Editing by Daniel Wallis)