President Bush on Wednesday nominated a physician and health care economist to head the Food and Drug Administration.

Dr. Mark McClellan, a member of the president's Council of Economic Advisers, posed for photographs in the Oval Office to make the nomination official, while his brother, deputy White House press secretary Scott McClellan announced it to reporters down the hall.

The Senate will have to confirm Mark McClellan's nomination.

"Dr. McClellan has impressive credentials both as a physician and economist. I look forward to learning more about his views on issues critical to the FDA," said Sen. Edward Kennedy, D-Mass., who heads the committee that would consider the nomination.

McClellan is best known for studies of the economic and policy factors that influence medical treatment conditions and helped draft Bush administration policy on prescription drug coverage for older people.

The FDA job is very different, heading an agency that regulates the safety of drugs, medical devices, food and cosmetics, products that make up a quarter of the national economy. Indeed, the FDA isn't supposed to consider the costs of a treatment, just whether it works and is safe enough to be used.

The agency has been leaderless since Bush took office, as the administration faced an impasse with Kennedy, who insisted the next commissioner have no close ties to any industry regulated by the FDA. McClellan appears to meet that test.

Kennedy's Senate Health Committee knows McClellan well from other work on health issues. But senators are likely to ask how much McClellan knows about the FDA.

Supporters say McClellan, a former professor of economics and medicine at Stanford University, has developed innovative ways to study patient care that could bring a fresh perspective to FDA. The Bush administration also considers him an attractive candidate because he has a good relationship with many lawmakers.

McClellan is a former practicing internist. Recent FDA chiefs have all been physicians.