In a high-level reshuffling at the Commerce Department, Donna C. Tuttle is slated to move up from undersecretary of travel and tourism to the number two job in the department, and W. Allen Moore, chief of staff to the Republican minority on the Senate Commerce Committee, will become undersecretary in charge of international trade, administration officials said yesterday.

The announcement of the appointments, expected to be made soon, ends months of confusion within the department. During that time, Commerce Secretary C. William Verity withdrew his support for the number two job from Bruce Smart, who then resigned as undersecretary.

Tuttle, the wife of White House personnel director Robert Tuttle, will replace former Ohio congressman Clarence J. Brown, who resigned in January as deputy secretary. A former Los Angeles school teacher who served as campaign finance director in George Dukmejian's 1982 race for governor of California, Tuttle took the undersecretary's job in 1983.

Until last month, Smart was expected to be promoted from undersecretary for international trade to the job of deputy secretary.

Because of "a difference in management styles," Verity withdrew Smart's name for the deputy secretary position, but invited him to remain as undersecretary.

Instead, Smart resigned Feb 22. He said he will become international trade adviser to the presidential election campaign of Vice President George Bush.

Moore takes on an assignment that is one of the most visible in the department, and he is expected to play a major role in negotiations with Congress over the shape of a trade bill now in House-Senate conference.

His appointment comes as a surprise, since he was not among those considered contenders for the job.