Washington: Barack Obama, who appeared on the cusp of winning the Democratic presidential nomination, has begun a top-secret search for a running mate, officials said today.

Obama has asked Jim Johnson, the former CEO of government-run mortgage lender Fannie Mae to begin vetting potential vice presidential picks, Democratic officials said on condition of anonymity because the campaign wants to keep the process quiet. Johnson did the same job for Democratic nominees John Kerry in 2004 and Walter Mondale in 1984.

Obama has been carefully trying not to alienate rival Hillary Rodham Clinton and her supporters by declaring himself the victor in the nomination race, but he has increasingly looked beyond her to focus on certain Republican nominee John McCain.

Obama refused to confirm Johnson's role when The Associated Press asked him about it.

"I haven't hired him. He s not on retainer. I'm not paying him any money. He is a friend of mine. I know him," Obama said. "I am not commenting on vice presidential matters because I have not won this nomination."

Some Democrats are calling on Obama to pick Clinton as his vice president. Clinton spokesman Howard Wolfson said today, "There have been no discussions with the Obama campaign about Senator Clinton being the VP".

Obama leads Clinton in the delegate count and it is virtually impossible for her to catch up with only three primaries remaining. He needs just over 60 delegates to clinch the nomination, which he is likely to get from the final contests and superdelegates, party leaders who can vote as they please.

Source : PTI