SANTA BARBARA, CALIF., SEPT. 3 -- President Reagan today unveiled a Commission on Privatization and instructed it to recommend, within six months, ways "to end unfair government competition and return government programs and assets to the American people."

Reagan named University of Chicago economics professor David F. Linowes, a Democrat, to head the bipartisan commission, which has the broad mandate of reviewing all federal activities to see which ones could be better performed by private industry. A White House fact sheet said the commission also "is expected to examine the potential for the sale and transfer of excess federal assets."

Others named to the commission include Melvin R. Laird, a former defense secretary; James T. McIntyre, a former director of the Office of Management and Budget, and Walter Wriston, a former Citicorp chairman.

Linowes, who was flown to Santa Barbara by the White House and who spoke in place of the daily briefing usually given by spokesman Marlin Fitzwater, said he has no preconceptions about what the commission will recommend, adding that "the greatest disservice I can do would be to express my own opinions."

In the course of the 15-minute briefing, Linowes said that federal programs to be examined will include everything from government housing to the prison system. He also offered the view that the transfer of federally owned housing units to private housing succeeded in Great Britain, where it has been an element of Prime Minister Margaret Thatcher's attempts to broaden private ownership.

Linowes said some activities will have to remain under government supervision because it would be "realistically impossible" for private industry to make a profit in running them. Pressed for examples, he cited the federal welfare program.

Reagan said he was appointing the commission to fulfill the commitment he had made July 4 in announcing his program for an "Economic Bill of Rights." The program's central features include constitutional amendments that would require a balanced budget, give the president a line-item veto for appropriations bills and require more than a majority vote in each house of Congress to raise taxes.

Privately, administration officials said there is little likelihood of any of these measures ever emerging from Congress. As a result, the White House is looking increasingly at administrative actions or regulatory changes that Reagan could promulgate without congressional approval during his remaining 16 months in office.

The timing of the commission's announcement, however, may have more to do with the dearth of White House actions during the final week of Reagan's 25-day California vacation. A White House official who was asked about the timing replied, "This just seemed like a good week to do it."

Other commissioners are:

Annelise Graebner Anderson, a senior fellow at the Hoover Institution in Palo Alto, Calif.; Michael D. Antonovich, a member of the Los Angeles County board of supervisors; Walter Bish of West Virginia, president of the Independent Steelworkers Union; Sandra Mitchell Brock of the District, government relations adviser for Heron, Burchette, Ruchert & Rothwell; New Mexico Gov. Garrey Carruthers (R); Richard Fink of the District, founder of Citizens for a Sound Economy; George Priest of Connecticut, a Yale Law School professor, and Ralph L. Stanley of New York, a senior vice president of the Municipal Development Corp.