A survey of 190 Washington area businesses has found that the majority -- 168 -- would use Dulles International Airport if additional flights were scheduled at Dulles.

The survey, funded by the Committee for Dulles, a group representing many citizens groups and business in the area, also found that 65 firms that now use Dulles less than 20 percent of the time would use it 90 percent of the time if airlines at Dulles flew more frequently to more cities.

The survey is the latest salvo in the continuing war over use of the Dulles and National airports, both in Northern Virginia.

Virtually all major airlines -- and Congress -- contend that National is the only airport in the Washington area that travelers want to use. A month ago, however, USAir Chairman Edwin I. Colodny broke ranks in a speech here and suggested that facilities at Dulles be improved and that National be closed as soon as the changes at Dulles are made -- the position taken by most area planning agencies, most area governments and dozens of area citizen groups.

In 1962 Congress authorized construction of Dulles to replace National as the principal airport for Washington, but since then both Congress and successive administrations have balked at forcing airlines to transfer flights from close-in National to Dulles, which is 26 miles from the District.

National has continued to increase its business, while Dulles has been losing both passengers and airlines. Five airlines left Dulles last year, although two have returned or soon will. Dulles had 2.6 million passengers last year, a 26 percent decline from the year before. National, with 14.5 million passengers last year, suffered a slight decline, 4.5 percent, which is comparable to passenger losses for the entire airline industry.

The Committee for Dulles believes its survey, which was conducted by the Systems Analysis & Research Corp. of Washington, challenges the airline industry contention that business travelers prefer National.

Of the 190 companies that responded to the survey, "all but 22 state that they would use Dulles for more than half their trips if service were available."

Most of the firms contacted are in Fairfax and Loudoun counties, but the survey included businesses in Montgomery and Prince William counties, the District and areas as far away as Martinsburg, W. Va.

The survey found that of 76 companies "in areas which are equally convenient to both Dulles and National," 66 would prefer Dulles for more than half their business trips, even though 45 said they now use Dulles less than 20 percent of the time.

Under the Carter administration, the Federal Aviation Administration (FAA), which operates Dulles and National, proposed some restrictions on National to help reduce noise and traffic generated by the airport.

The restrictions, which were to take effect April 26, last week were postponed another six months by the Reagan Administration..

The proposed restrictions would end late-night flights and reduce the number of commercial jets using the airport.

But the FAA would allow National to handle flights to cities 1,000 miles away, replacing the present 650-mile limit that was designed to keep National a short-haul airport and force airlines to use Dulles for longer flights.

The proposed FAA regulations also would permit further growth at National to a maximum of 17 million passengers a year. The decrease in number of planes and increase in passengers would be accomplished by allowing the large but quiet, wide-bodied jets to use National, which are not prohibited