The "Washington hotel with the decidedly British air," the new Henley Park Hotel at Massachusetts Avenue and 10th Street NW, is nearing completion and has named William N. Trimble as general manager.

The District's latest luxury hotel is located on the site of the old Tudor Hall, a former apartment building. The hotel, which is two blocks from the new D.C. Convention Center, is scheduled for completion in March 1983.

Coakley & Williams Inc. is the owner, builder and operator of the hotel in partnership with Charles C. Wilkes, a Washington attorney and developer.

The hotel's developers are restoring and rebuilding the seven-story, 64-year-old Tudor-styled structure. All electrical wiring, plumbing, interior walls and furnishings will be new. Some panelling and ceiling moldings from the lobby level have been restored and will be incorporated in the new design.

The hotel's 98 suites and guest rooms will be complimented by several meeting rooms, a lounge, a library, and special events rooms.

The Henley Park will offer traditional British luxury accomodations. Jack Daniel, director of marketing for the hotel, has traveled to England to secure original art and antique furnishings for the hotel. Two chefs from England will help establish the hotel's gourmet restaurant.

Trimble was literally born into the luxury hotel business while his father was managing Philadelphia's Warwick Hotel in the 1930s. As a young man, he worked as an assistant bellman at the Claridge Hotel in Atlantic City.

After graduation from Cornell University's School of Hotel Administration, he joined the executive staff of Philadelphia's Bellevue Stratford Hotel. He most recently was general manager of the Barclay Hotel there.

Coakley & Williams, developers and operators of hotels and commercial properties in the Washington area, is celebrating its 20th anniversary this year. The corporation is headquartered in the new 16-story Maryland Trade Center building in Greenbelt, which the corporation owns. The firm was founded by Neil T. Coakley, chairman of the board and President Fred G. Williams.

Dividends: Citizens Bancorp declared a quarterly dividend of 75 cents per share, payable Dec. 31 to stockholders of record Dec. 10. . . .Best Products declared a quarterly dividend of 8 cents per share, payable Dec. 15 to stockholders of record Dec. 1. . . .Doughties Foods Inc. declared a dividend of 3 cents per share, payable Jan. 3 to stockholders of record Dec. 10. . . .James Madison Ltd. the holding company of Madison National Bank, has declared a semi-annual dividend of 50 cents per share, payable Jan. 3 to stockholders of record Dec. 20. . . .Geico Corp. has declared a quarterly dividend of 14 cents per share, payable Dec. 31 to stockholders of record Dec. 6. . . .

American Security Corp. has declared a quarterly dividend of 35 cents per share, payable Jan. 3 to stockholders of record Dec. 17. . . .First Virginia Banks Inc. has declared a dividend of 17 cents per share, payable Jan. 10 to stockholders of record Dec. 31. . . .Reynolds Metals Co. has reduced its quarterly dividend by 45 percent on its common stock. The dividend, payable Dec. 21 to stockholders of record Dec. 1, was reduced from 45 cents to 25 cents. Company officials blame a continuing worldwide recession and depressed demand in most of aluminum's major markets for the lower dividend.

McCormick & Co. Inc. has bought a 70 percent interest in a Brazilian spice packing company for about $2 million, payable over 3 years in Brazilian currency.

The foreign packer markets spices primarily within Brazil and had sales of about $5.5 million in 1982, McCormick said.

Panasonic Corp. will shift its Mid-Atlantic division headquarters from New Jersey to the Baymeadow Industrial Park in Glen Burnie next year.

Construction of Panasonic's $5 million facility that will be headquarters for sales and product distribution is expected to be completed in August.

Panasonic expects to employ about 150 people.