WASHINGTON (CNN) - President Bush announced Tuesday that he has nominated Rob Portman, currently the U.S. trade representative, as the new director of the Office of Management and Budget.

The position was vacated by Josh Bolten when he was made the new White House chief of staff last month.

President Bush made the announcement in the Rose Garden, saying that Portman's "talent, expertise and record of success are well-known on Capitol Hill."

The announcement comes on the heels of a staff meeting Monday, when Bolten told senior White House aides to be prepared for personnel changes in the coming days to "refresh and re-energize" the Bush administration.

Portman was appointed by Bush to the U.S. trade representative post in April 2005.

Prior to that, he was a congressman from Ohio. He also served as associate counsel to the president and director of the White House office of Legislative Affairs while George H.W. Bush was in the Oval Office.

Sources told CNN that Deputy U.S. Trade Representative Susan Schwab will replace Portman.

-- CNN White House Correspondent Ed Henry contributed to this report

________________

For more economic news, click here.