Commerce Secretary Malcolm Baldrige detailed yesterday for the first time what the Reagan administration would like to see in a new Department of Trade--virtually all the functions of the present Commerce Department, with the White House Office of the U.S. Trade Representative tacked on.

But he emphasized that the final makeup of the new department, proposed a week ago Monday by the White House, depends on negotiations with key members of Congress.

It remained unclear from the Baldrige outline, however, whether his vision of the new department would dovetail with the proposal of Sen. William V. Roth (R-Del.), who is sponsoring legislation calling for a "lean, mean" trade department. Baldrige said he would like to meld the administration proposal into the Roth bill, but Roth has criticized the Commerce Department as "a grab bag of unrelated functions" unequal to the task of managing America's trade policy.

A Roth aide said "everything is wide open" on the department's makeup as Commerce officials meet with Senate staff members on the bill. "Baldrige is giving his views, but that is not necessarily what will come out," the aide said. "We like our bill as it is. But we're willing to listen to their proposals."

According to the picture Baldrige drew yesterday in a meeting with reporters, the only major agency of Commerce missing from the proposed trade department would be the National Oceanic and Atmospheric Administration (NOAA), which contains the National Weather Service and accounts for about 60 percent of Commerce's budget and 40 percent of its manpower.

He declined to commit himself on where NOAA might go and said there is a slim likelihood it could remain within the new organization.

Every other major agency of the Commerce Department--the Census Bureau, the National Bureau of Standards, the Patent and Trademark Office--would be included in the new department, along with Commerce's existing International Trade Administration, Baldrige said. Under the Baldrige outline, the new department would include about 20,000 of Commerce's 36,000 employes.

He said these agencies from Commerce would give the new department the "muscle" that would allow it to be "mean."

To meet a statutory requirement, the head of the new department would carry the title of special trade representative as well as being secretary of trade, Baldrige said.

The 130-person trade representative's office would be one of the agencies of the new department, but would retain its identity as the office responsible for the formulation of trade policy and the handling of trade negotiations.

He said President Reagan has put the proposal on a fast track and hopes for its passage this year. As for his future, Baldrige said, "I would be pleased enough to get this new department through that I would not lift a finger" to become its head. He added that "it wouldn't bother me at all" if the present trade representative, William E. Brock, got the job.

"I made a living in the private sector before and I can go back and do it again--I hope," Baldrige said.

Reorganization, he said, is important to ending the nation's record trade deficit, which he said could climb as high as $60 billion this year. He blamed a decline in exports for the loss of 1 million jobs since the beginning of 1980.

As now set up, Baldrige said trade policy lacks a vigorous advocate. There are, moreover, "gray areas of responsibility," an "excessive" amount of consultations, and a lack of accountability--all of which "tend to weaken our trade thrust," he said.

Nonetheless, Baldrige acknowledged that the Agriculture Department with its strong and well organized constituency would retain responsibility for farm exports--which amounts to about 40 percent of all U.S. overseas sales.

Besides NOAA, offices still in limbo under the picture Baldrige drew are the 458-person Economic Development Administration and the 224-person Minority Business Development Agency.