US New Mexico Governor Bill Richardson has withdrawn as President-elect Barack Obama's nominee for commerce secretary, NBC reported on Sunday.

Obama has accepted Richardson's decision, according to the report, and a federal grand jury is investigating how a California company that contributed to Richardson's political activities won a lucrative New Mexico state contract.

US President-elect Barack Obama listens as New Mexico Governor Bill Richardson (L) speaks after being introduced as nominee for commerce secretary during a news conference in Chicago December 3, 2008. [Xinhua/Reuters]

Richardson becomes the first nominee of Obama's cabinet to withdraw. The president-elect will take office on January 20.

"Let me say unequivocally that I and my administration have acted properly in all matters and that this investigation will bear out that fact. But I have concluded that the ongoing investigation would have forced an untenable delay in the confirmation process," Richardson said in a statement released by Obama's transition team.

"It is also because of that sense of urgency about the work of the Commerce Department that I have asked the President-elect not to move forward with my nomination at this time. I do so with great sorrow. But a pending investigation of a company that has done business with New Mexico state government promises to extend for several weeks or, perhaps, even months," Richardson said.

Obama said in a statement that he had accepted Richardson's decision with "deep regret" and that he would move quickly to fill the position.

Obama said Richardson's decision showed "his willingness to put the nation first that he has removed himself as a candidate for the Cabinet in order to avoid any delay in filling this important economic post at this critical time."

(Xinhua News Agency January 5, 2009)