The High Court in London has refused to block the extradition of British solicitor Jeffrey Tesler to the United States.
Mr Tesler, 62, from London, is accused by US authorities of involvement in a conspiracy to channel bribes to senior officials in Nigeria.
He was arrested last year following an extradition request from the US.
It is alleged he channelled money to Nigerian officials to obtain contracts valued at more than $6bn (Â£4bn).
Bribes were allegedly paid from a $132m (Â£88m) slush fund to influence the awarding of a construction contract for a natural gas plant on Bonny Island in Nigeria.
Mr Tesler was accused of acting as the middleman in the conspiracy, said to have occurred between 1994 and 2004.
Mr Tesler, who has dual British-Israeli nationality, was arrested at the request of the US government after a grand jury indictment was filed at a US district court in Houston, Texas, in February 2009.
He has lived in Tottenham, north London, for more than 50 years.
His legal team has argued that the conduct complained of did not occur in the United States, and there were “insufficiently substantial links” between it and the US to legally justify extradition.
They also argued that his access to a fair trial was compromised by the passage of time because the alleged crimes date back as far as 1994.
But lawyers for the US government have said the extradition request satisfies the requirements of UK law and that Mr Tesler’s removal to America would be neither unjust nor oppressive.
At the High Court hearing, Lord Justice Pill and Mr Justice Roderick Evans said the fact that the eventual “harm” might be in Nigeria did not detract from the US connection.
This was that the essence of the American offence claim was bribery of foreign officials.
They also said extradition was not barred by reason of the passage of time.
Lord Justice Pill said the joint venture in which Mr Tesler was alleged to have participated had a strong American connection, because one of the four companies involved was both incorporated in and had its headquarters in the US.
“A conspirator does not escape his liability to be extradited as a participant in such a scheme, as a result of which very substantial sums of money were planned to be made in the United States, by remaining out of the United States,” he said.
“The appellant was taking part in a joint enterprise with United States entities, one of the objects of which was to benefit substantially a United States company.
“The effects of his actions were to be felt in the United States and were intended to be felt there. A United States entity was intended to be one of the beneficiaries of his corrupt conduct.”