Pay raises of 16.8 percent for 38,000 top government executives have been put on hold for at least four months by the House Appropriations Committee.

Many of the oficials, who range from heads of agencies to scientists and administrators further down the bureaucratic totem pole, live and work in the metro Washington area. Most have not had a raise since 1977, although pay of subordinates and industry executives have marched upward as has the cost of living.

The House unit voted yesterday to extend through September (the end of this fiscal year) the freeze on top level pay. It limits most career and political appointees to a maximum of $50,112.50 per year. That pay "cap" or ceiling is due to expire June 4 and it would mean catch-up raises for most of the upper level workers.

Most of the government's million-plus white collar workers (300,000 here) have had regular October pay raises representing a partial catch-up with wage gains in the private sector.

Last year white-collar (classified) federal workers got a 9.1 percent raise. President Reagan has proposed a maximum boost of 4.8 percent this October. But executives have been frozen out of recent raises (the last one they got was 5.5 percent in October 1977), and if the Senate and House go along with the extension in the Supplemental Recision and Continuing Appropriation Bill okayed by the committee, the executive pay cap will stay on until at least this fall. Thousands of federal executives in Grades 18, 17, 16 and down through the senior ranks of Grade 15 have been caught up by the pay ceiling and all now make the same $50,112.50 salary even though their duties and responsibilities vary greatly.

Congress, for political and economic reasons, has been reluctant to boost its own pay (members now get $60,662.50 in straight salary) and has refused to boost salaries of "unelected bureaucrats" if senators and representatives can't get more.

Rep. Frank Wolf, (R-Va.) who represents a sizeable chunk of the frozen executive population, made a strong appeal to the Appropriations Committee to give top-level feds some kind of raise. Wolf and Jerry Shaw, president of the Senior Executives Association, argue the government is losing many of its best executives who retire early and/or take better-paying jobs in the private sector where executive salaries are often higher. But the committee, probably reflecting the economy mood of the Congress as a whole, rejected the argument and voted to keep the pay lid for executives through Sept. 30.

There is still a chance, of course, that some kind of pay raise could authorized by the Senate or House, or that the language in the continuing appropriation bill could be chopped out, or amended. But not much of a chance.

President Carter recommended that Congress let the pay cap expire, and that executives be allowed the 16.8 percent catch-up representing raises denied them in the past couple of years. President Reagan at first endorsed the concept, but later came out against pay raises.

Meantime, the administration is reportedly have some problems persuading the kind of private industry hot shots it wants to recruit for government service. They're reluctant to give up their corporate salaries and stock options so they can come here and be investigated, grilled and second-guessed six times a day by politicians, pressure groups and the press.

SEA President Jerry Shaw says lobbying already has started in the Senate to get the cap off in June, and give executives the same catch-up raises other federal workers have been allowed.