President-elect Barack Obama's close friend, political ally, and his choice for commerce secretary, New Mexico Gov. Bill Richardson has withdrawn his consideration for the nominated post. Citing the main hindrance in the way of his confirmation, Richardson mentioned the pending "pay-to-play" federal inquiry that involves one of his political donors.

Counted among the country's best-known Latino politicians, Richardson, 61, said that he expects the investigation to last weeks or even months, which could prolong his confirmation hearings and sidetrack the new administration as it tackled the economic crisis.

In a statement, Richardson said: "Given the gravity of the economic situation the nation is facing, I could not in good conscience ask the President-elect and his administration to delay for one day the important work that needs to be done."

Richardson, who is a former energy secretary, and UN ambassador under President Bill Clinton, thought that, given the circumstances, his confirmation could never be a sure thing, even with the Democrats having a decisive control of the Senate. He was deemed to become the highest-profile Hispanic in Obama's administration.

Visibly a blow to one of the smoothest presidential transitions, Richardson's withdrawal has become the first political casualty in Obama's Cabinet. Obama has accepted the decision "with deep regret," saying: "It is a measure of 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."