EDIT CONTAINS 4:3 MATERIAL

A U.S. federal judge has sentenced Russian arms dealer Viktor Bout to 25 years in prison for agreeing to sell weapons to undercover U.S. agents.

Bout, known as the merchant of death, maintained his innocence in court Thursday-- and at one point gestured to federal agents and said 'God forgive you'.

Bout's lawyer thanked the judge for handing down the minimum sentence but said his client will appeal.

(SOUNDBITE) (English) ALBERT DAYAN, ATTORNEY FOR VIKTOR BOUT, SAYING:

" The judge could have given him as much as life and he is grateful to her for carefully considering the facts and circumstances of this investigation and prosecution. And he intends to move forward in the court of appeals and if necessary to the United States Supreme Court. He maintains his innocence."

Federal agents arrested Bout in Thailand in 2008 during a sting operation in which they posed as members of the Colombian rebel group FARC.

During Thursday's sentencing, the judge said the fact that Bout's conduct was a result of a government sting operation was a mitigating factor despite his long history of arms dealing.

Julie Noce, Reports