(REUTERS) -- President Barack Obama will ask Congress for authority to merge the agency that negotiates U.S. trade deals into the Commerce Department, a White House official said on Friday, in an effort to trim the government amid voter concerns about deficits.

Obama was set to announce the request, which could open the door to further consolidation in Washington, in a late morning address at the White House.

He will seek a vote in Congress within three months on the proposal to put the Office of the U.S. Trade Representative (USTR) and other groups dealing with exports under one roof at the Commerce Department - something that has been under discussion for years.

Senate Finance Committee Chairman Max Baucus, one of Obama's fellow Democrats, and some other senior members of Congress have expressed concern that the USTR, a small cabinet-level agency of some 240 career employees, could lose its focus if forced into a larger department.

But Obama is set to cast the move as part of his goal to double U.S. exports within five years, which he said this week the United States may meet ahead of schedule.

With the November presidential election nearing, the White House has been working to highlight Obama's efforts to get things done in Washington despite a gridlocked Congress.

Friday's request also addresses concerns raised by fiscally conservative voters and flagged by Republican contenders for the White House about the expanding federal government and Washington's large deficits.

(Reporting by Laura MacInnis and Douglas Palmer, Editing by Vicki Allen)