WASHINGTON (AP) _ Roger D. Semerad, an assistant secretary of Labor for the last two years, is resigning to become a senior vice president of the Burson-Marsteller public relations firm, the firm announced Thursday.

At the Labor Department, Semerad has been responsible for the administration of $26 billion in federal programs, including the Job Training Partnership Act, federal unemployment insurance, the U.S. Employment Service and the Job Corps.

Prior to joining the Labor Department in September 1985, Semerad was executive vice president and a trustee of the Brookings Institution, a Washington-based think tank.

From 1977 to 1980, he was executive secretary of the Republican National Committee's policy advisory councils and was executive director of the 1980 Republican Platform Committee. Earlier, he served as an aide to Presidents Nixon and Ford.

Semerad is expected to start his new job at Burson-Marsteller's Washington office in early January.