NEW YORK (Reuters) - A former Rabobank trader from Britain on Monday avoided prison after cooperating with U.S. authorities investigating how traders manipulated Libor, the leading benchmark for pricing financial transactions, to the bank’s advantage.

Paul Robson, 47, was sentenced to time served and two years of supervised release by U.S. District Judge Jed Rakoff in Manhattan, who cited his decision to cooperate with the U.S. Justice Department for imposing a non-prison sentence.

“No crime of this kind can be prosecuted without cooperation,” Rakoff said.

Robson, who pleaded guilty to a conspiracy charge in August 2014, in court apologized for his actions.

Libor, or the London interbank offered rate, underpins trillions of dollars of financial products globally from mortgages to credit cards. The rate is based on what banks say they believe they would pay if they borrowed from other banks.

U.S. and European authorities have spent years probing whether banks tried to manipulate the rate to benefit their own trading positions.

The investigations have led to around $9 billion in regulatory settlements with financial institutions and charges against several individuals.

Those included Robson and six other former Rabobank traders charged by the U.S. Justice Department after the bank in 2013 reached a $1 billion deal to resolve related U.S. and European probes.

Prosecutors said Robson participated in a scheme with others to rig the U.S. dollar and yen Libor rates to benefit Rabobank’s trading positions, in which traders sought to influence the bank’s Libor submissions.

On behalf of prosecutors, he testified at trial against two other ex-Rabobank traders from the United Kingdom, Anthony Allen and Anthony Conti, who a federal jury found guilty in November.

In March, Allen and Conti were sentenced to two years and one year in prison, respectively. Both are appealing.

Robson’s sentencing came after another ex-Rabobank trader who pleaded guilty, Paul Thompson, was sentenced on Wednesday to three months in prison.

Two other Rabobank traders - Takayuki Yagami and Lee Stewart - have pleaded guilty and have yet to be sentenced. A seventh, Tetsuya Motomura of Tokyo, is considered a fugitive by the U.S. government.

The case is U.S. v. Robson et al, U.S. District Court, Southern District of New York, No. 14-cr-272.