A major financial company has cut off negotiations with the former US president, Mr Bill Clinton, to invite him as a speaker to a New York investment banking conference, in the light of new controversies surrounding Mr Clinton since his departure from the White House.

In another setback for the embattled ex-president, a number of leading Democrats criticised him yesterday at a Senate Judiciary Committee hearing in Washington over his last minute pardon for Mr Marc Rich, the fugitive trader living in Switzerland.

Several Republican Senators said they wanted to call Mr Clinton himself to ask why Mr Rich was pardoned without going through the proper judicial process.

The news of a cancelled speaking engagement is a major blow to Mr Clinton's prospects of making an income from the lecture circuit, as more may follow.

Saddled with millions of dollars in legal fees from previous scandals, he is relying on regular payments from speaking engagements at home and abroad.

Mr Clinton is due, for example, to deliver a keynote address at Trinity College Dublin later this year at the invitation of Independent Newspapers for a fee of around $100,000 (€108,909).

It became known yesterday that the London-based company UBS Warburg cancelled negotiations with Mr Clinton to speak at a conference in April as being not in the company's best interest. Complicating matters for UBS, which is the parent company of the US investment firm, Paine Webber, is the possible appearance of impropriety, as a senior UBS executive, Mr Pierre de Weck, wrote to Mr Clinton supporting a pardon for Mr Rich.

Last week the Wall Street securities firm, Morgan Stanley told angry clients that its decision to pay Mr Clinton a sum exceeding $100,000 for a speech in Florida on February 5th was clearly a mistake in the light of Mr Clinton's behaviour in office and since he left it.

Mr Clinton's scheduled speech at Salem College in Massachusetts next month has become an issue of partisan controversy, with Republican legislators in the state demanding that public money not be used to pay the $100,000 fee.

Speeches at the software company Oracle and the Firestone Respiratory Health in Ontario are to go ahead, though both companies said they had received complaints. On Capitol Hill yesterday, Democratic Senator Charles Schumer of New York said: "The pardoning of fugitives stands our criminal justice system on its head," and party colleague Mr Richard Durbin of Illinois stated it "certainly raises the appearance of impropriety".

Senator Russ Feingold of Wisconsin said he had suspicions about the Rich pardon because the financier's ex-wife, songwriter Denise Rich, donated hundreds of thousands of dollars to the Democratic Party.