Obama campaign says it raised $21.9 million in May

WASHINGTON (Reuters) - Barack Obama raised $21.9 million in May, his campaign reported on Friday, a day after the Democratic candidate said he would reject public financing for his presidential bid.

The Illinois senator's campaign said it had $43.1 million in the bank at the end of the month, with debts of about

$304,000.

The disclosure followed Obama's reversal on the question of whether he would take public financing, which drew sharp criticism from his Republican opponent, John McCain.

McCain's campaign said on Friday he raised almost as much in May -- $21.5 million. He spent $11.6 million and ended the month owing $1.27 million, with $31.5 million in the bank, up $10 million from the end of April. During the primary season, he raised $96 million.

Obama's fundraising figure for May is less than the $30.7 million he raised in April. At the end of that month, he had $46.6 million in the bank, with debts of $2 million.

His campaign has racked up record-breaking fundraising numbers in a presidential run that will be the most expensive in U.S. history.

It raised about $36 million in January, $55 million in February and more than $42 million in March.

Obama is the first U.S. presidential candidate to bypass the public financing system since it was created after the Watergate scandal in the mid-1970s.

He built a formidable grass-roots financial machine during his primary battle against Sen. Hillary Clinton of New York, raising more than $265 million from more than 1.5 million donors, many of whom gave in small increments.

(Editing by Chris Wilson and Eric Walsh)