Marriott Corp. and restauretaur Ulysses (Blackie) Auger announced yesterday they will build a 350-room, hotel at 22nd and M Streets N.W., beside and above Blackie's House of Beef.

The hotel will be the first built in Washington by Mariott, which was founded here 50 years ago. Marriott officials indicated it may be followed by a second one near the newly approved convention center.

Auger will own the hotel and Marriott will run it, as The Washington Marriott. Although no cost was announced, industry sources place the project in the $17-20 million range and estimated it will employ 350 persons.

The developers hailed the hotel as the first of the private projects needed to assure construction of the convention center, but that view was questioned on Capitol Hill.

Congressional financing for the convention center is contingent upon commitments, restaurants and other facilities that will generate enough new taxes to support the center's deficit.

"One of the conditions (for Congressional approval of the center) was private investment. We stepped up to be first," Auger said.

But Sen. Patrick Leahy (D-Vt. chairman of the Senate District appropriations subcommittee, says he won't count projects not directly dependant upon the convention center.

Auger has long talked of building a hotel adjacent to his flagship restaurant - the first and biggest of the 15 he owns - and only recently reached agreement with Marriott to run it.

Construction of the nine-story hotel tower and adjacent public rooms is to start this summer, with the opening in the fall of 1980.

"The certainly of the convention center has helped us move this project ahead," said Marriott's vice president for corporate affairs, Tom Burke.

Burke said Marriott also is considering building another hotel near the convention center site. "We've talked about it. We want to see the plans. We could be interested. We'd like to be in that neighborhood," he said.

"The convention center changes the whole complexion of Washington," said Burke, predicting the city will become "one of the five best convention cities in the country" - along with Chicago, New Orleans, San Francisco and New York.

Marriott on Monday will open its largest hotel, with 1,214 rooms, on North Michigan Avenue in Chicago.

The partnership with Auger will preserve Blackie's House of Beef and its serindipitous seccession of rooms, stained glass windows, fireplaces and army of customers. THe hotel tower will be built over the restaurant, with the lobby on 22ns St., N.W., just north of Blackie's entrance.

Marriott will operate the other food service facilities in the hotel, which will have a ballroom big enough to seat 650.

A second-floor shywalk - believed to be the first in a private development in Washington - will link the hotel to the new Thurman Arnold office building, to the east.

Work is expected to begin later this month on that building, which will house of offices of the Arnold and Porter law firm. Auger is a partner in that project as well, with builders James Clark and Oliver T. Carr.

For Marriott, the new hotel will be the sixth in the Washington metropolitan area, and will give the chain nearly, 2,300 rooms here.

Marriott expects to open a 300-room hotel in Wisconsin Avenue in Bethesda in December, and in June will begin a 200-room addition to the Key Bridge Marriott, which now has 372 rooms.

A 40-room addition to Marriott's 301-room Crystal CIty hotel is also scheduled for this summer. There is another 450-room Marriott at Twin Bridges and a 213-unit operation at Dulles Airport among the 52 hoteks the company owns.

With a $90 million investment in hotels, restaurants and airline food kitchens in the metropolitan area, Marriott says it does about $160 million of business a year here, has an $80 million payroll for 13,000 employes and pays $6 million in taxes.

The planned Marriott hotel is one of several new onves in the District of Columbia. Nearby on Pennyslvania Avenue is the Guest Quarters apartment hotel, set to open later this year. At 29th and M Streets, N.W. the Four Seasons hotel is under construction. The Fairfax Hotel at 21st St. and Massachusetts Ave., N.W. is undergoing a major renovation. CAPTION:

Picture 1, Ulysses (Blackie) Auger looks over plans for the new Washington Marriott on the hood of a car parked where the hotel lobby will be built. Hotel rooms will be in a long, narrow building above Blackie's House of Beef. A skywalk will link the hotel with the new proposed Thurman Arnold building. By Ellsworth Davis - The Washington Post; Picture 2, An artist's rendering of the proposed Washington Marriott above Blackie's House of Beef at 22nd and M Streets NW.