An advisory group to Mayor Marion Barry recommended yesterday that he support raising the city's drinking age to 21 for all alcoholic beverages, a prelude to a definitive policy statement expected soon from Barry.

Barry has not taken a position on the matter, but instead has supported arguments on both sides. A spokesman said recently that the mayor was "leaning" toward support of the 21-year minimum.

The minimum age for buying beer and wine in the District is 18, while the minimum for liquor purchases is 21.

"We think lives will be saved and injuries avoided by raising D.C.'s drinking age to 21, which is the primary reason for this recommendation," concluded the report from the Mayor's Advisory Committee on Traffic Safety.

"But we also believe a vigorous antidrunk-driving educational and enforcement campaign, aimed at all age groups, should be continued and enhanced in the District and its surrounding jurisdictions," the report added.

Federal legislation was enacted in 1984 to withhold highway funds from any state that fails to raise its minimum drinking age to 21 by Oct. 1, 1986.

As a result, a number of states across the country, including Maryland and Virginia, increased their drinking ages.

Despite the prospective loss of about $2.6 million in highway funds for fiscal 1987 and more than $5 million in fiscal 1988 and subsequent years, the D.C. Council's Committee on Consumer and Regulatory Affairs voted 4 to 1 last year against a higher drinking age.

Congressional subcommittees that oversee the city's budget started pressuring the city last year to make the change, and Barry has been asked to address the issue at a hearing tomorrow of the Senate Appropriations subcommittee on the District.

The advisory committee adopted its report by a vote of 8 to 2, Chairwoman Judith L. Stone said in a letter that accompanied the report to Barry yesterday. It cited concerns about drunk driving and alcohol-related deaths among young people.

It also noted an estimate by the Washington D.C. Restaurant and Beverage Association that the sales tax loss to the District government from the change would be about $6 million a year.

The report said that 42 states now have a 21-year drinking age and that more are likely to conform soon. The panel said the District could get a "negative public image" if it did not do so, as well.

The panel proposed phasing in the change to "grandfather" in persons who now are 18, 19 and 20.

Michael Maher, executive director of the restaurant and beverage association and a panel member, did not concur with the report. He recommended keeping the 18-year drinking age for beer and wine and said the city should aggressively punish drunk drivers.