NEW YORK - PRESIDENT-ELECT Barack Obama has chosen New Mexico Governor Bill Richardson to be commerce secretary, adding a prominent Hispanic and one-time Democratic presidential rival to his expanding Cabinet.

Mr Obama planned to announce the nomination after Thursday, the Thanksgiving holiday, according to a Democratic official familiar with the discussions.

The official was not authorised to speak publicly about the negotiations and did so on condition of anonymity.

Mr Richardson, 61, had a distinguished and visible career in Washington before returning to New Mexico, where he was elected governor in 2002.

Mr Richardson served as UN ambassador under President Bill Clinton and later as energy secretary. He was in the House of Representatives from 1983 to 1997.

Mr Clinton sent Mr Richardson on several high-level diplomatic missions while he was in Congress, including direct talks with Iraqi leader Saddam Hussein.

In Mr Richardson, Mr Obama will get a secretary of commerce who has been described as relentless and competitive, with a jocular sense of humour.

Mr Richardson is a seasoned international negotiator who mediated with North Korea over the downing of two US Army helicopter pilots; hammered out a deal with Saddam Hussein for the release of two US oil workers; won the release of three Red Cross workers held captive by Sudanese rebels; and was later sought out by the North Koreans to discuss nuclear issues.

His success, said Mr David Goldwyn, national security deputy at the United Nations in the late 1990s, stems from the many different facets of his personality - whether it's the athlete (he bonded with Mr Fidel Castro over baseball), the tireless adversary (he spent four hours at the table trying to persuade President Laurent Kabila to let a UN team investigate massacres in Congo) or the regular guy.

'Mr Richardson is all about crashing through boundaries,' Mr Goldwyn said in 2007.

'He says hello to the security guy, and if he's Hispanic he'll say something in Spanish. If he's African-American, he might call him 'his brother.''

'People think it's undisciplined and so they think he's undisciplined, and that is a mistake. ... His personality gets him in the door. From there, he's got to deliver the message, he's got to be persuasive, and he's got to secure the objective. That's where the other part of his personality comes in: his relentlessness.'

Mr Richardson ran for the Democratic presidential nomination but dropped out in January after a poor showing in early contests. He went on to endorse Mr Obama at the height of the Illinois senator's primary contest with Mrs Hillary Rodham Clinton, angering many Clinton supporters who viewed the endorsement as a disloyal snub.

Mr Obama considered Mr Richardson to be secretary of state and brought him to Chicago to discuss the job. The president-elect is on track to name Mrs Hillary Rodham Clinton to the top diplomatic post and was expected to announce the pick after Thanksgiving.

Mr Obama was set to name New York Federal Reserve Bank president Timothy Geithner as his treasury secretary on Monday, in his first official Cabinet announcement.

Mr Obama also planned to name Mr Lawrence Summers to lead the National Economic Council.

Several other candidates for Cabinet posts have emerged in recent days.

Mr Obama's choice for attorney general is Mr Eric Holder, who held the No. 2 slot in the Justice Department under Bill Clinton. The president-elect's aides have also encouraged speculation that Defence Secretary Robert Gates would remain in office for an interim period.

Other selections include former Senate Majority Leader Tom Daschle of South Dakota as secretary of health and human services and Arizona Governor Janet Napolitano, likely to be named as homeland security secretary.

Additionally, retired General James Jones, a former Marine Corps commandant and Nato commander, appeared to be the top contender to be national security adviser. -- AP