The owners of The Gray Line, the bus company that hauls millions of sightseers around Washington, have decided to abandon the bus business here and sell out to another line.

Gray Line has applied to the Interstate Commerce Commission and the Washington Metropolitan Area Transit Commission for approval to sell its routes, 15 buses and other facilities to Atwood's Transport Lines, which runs the Gold Line charter buses.

If the sale is approved, Gold Line will take over not only Gray Line's sightseeing tours of Washington attractions, but also is small commuter and charter operation.

In recent years, the Washington Gray Line has been "very moderately profitable at best," said Dale Dullabaun, president of First Gray Line Inc. of Los Angeles.

Dullabaun's bus line is one of about 160 independent members of the Gray Line Sight-Seeing Association who operate under that name throughout the world.

Dullabaun said First Gray Line plans to end its Washington operations and concentrate its business activities on the West Coast, where it has several bus companies and other businesses.

Atwood's Gold Line, based in Tuxedo, Md., has agreed to pay $547,500 for the Gray Line operation, according to the application for sale made to the Washington Metropolitan Area Transit Commission. Atwood is owned by the Frank Martz Coach Co. of Wilkes-Barre, Pa.

The plan to combine the Gold and Gray lines is being fought by a group of Gray Line drivers who say they want a chance to buy the line themselves.

Jack Kileen, a spokesman for the Gray Line employes, said the drivers have hired a lawyer to oppose the sale before regulatory agencies.

Combination of the two lines, Kileen contends, would not only give a single company a virtual monopoly over local sightseeing and charter routes, but would move a major business out of the District of Columbia and cost about 100 Gray Line employes their jobs.

Drivers with as much as 35 years experience will be thrown out of work, Kileen said, because Gold Line has agreed to take over the Gray Line routes, but not the Gray Line contract with the Amalgamated Transit Workers Union.

Kileen said Gray Line officials "didn't take us seriously" when a group of drivers approached the company about buying the line to save their jobs. He said more than 50 employes had pledged 10 percent of their salaries to provide money for the purchase.

Dullabaun said the driver's group inquired about buying the line several weeks after negotiations began with Atwood's. The drivers never made a firm proposal or showed evidence they could come up with the necessary cash, he added.

Dullabaun said the Gray Line drivers will get "very generous severance pay - in some cases up to five weeks" - and will have a chance for a job with Gold Line, which also has a contract with the Amalgamated.

But Kileen said the Gray Line contract pays drivers up to $7.45 an hour for driving sight-seeing buses - and pointing out the attractions at the same time - compared with a $6-an-hour top for Gold Line drivers.

Dullabaun said the drivers "can do what they want to do, it won't change our plans. We've told the ICC that if the sale isn't approved, we'll have to shut down the line."

He said the company already has transferred some of its buses to the West Coast and would simply close its doors if the sale is blocked.

In addition to the sight-seeing buses that make daily tours of the capital's attractions, Gray Line has ICC operating rights to serve the Maryland race tracks and hauls commuters between Washington and Fairfax City, Sterling Park, Mantua and Greenbriar.

Atwood's Gold Line gets 90 percent of its revenues from charter services, said Ted Patton, traffic manager of the company that owns Atwood's. Gold Line operates one commuter line, serving Patuxent River, Md.

The Washington Area Metropolitan Transit Commission, will hold a hearing tomorrow on the proposed sale to Atwood. Legally the sale has to be "consistent with the public interest," and the drivers are contending the public interest includes protecting jobs.