WASHINGTON — Rep. Rob Portman, R-Ohio, was nominated March 17 as the next U.S. trade representative by President George W. Bush. His nomination is subject to confirmation by the Senate. Mr. Portman would replace Robert Zoellick, who is now Secretary of State Condoleezza Rice's top deputy. Mr. Portman is a member of the House Ways and Means and Budget committees. Rep. Ben Cardin, D-Md., and Mr. Portman have sponsored several bipartisan pension bills in the House to streamline regulations and make it easier for employers to offer retirement plans. The two were working on introducing their third major legislative pension package. Kyle Downey, a spokesman for Mr. Portman, said he did not know if the lawmakers would rush to introduce the bipartisan pension bill, adding that Senate confirmation of Mr. Portman as trade representative could take a month or two. Mr. Downey also could not say who might replace the Ohio lawmaker as the new Republican champion of pension issues on the powerful House tax-writing committee, which oversees pension legislation.