The Metropolitan Washington Council of Governments approved a regional conference yesterday to study acquired immune deficiency syndrome (AIDS), a growing problem the council said affects suburban as well as urban areas.

"We have first of all a right to know what the extent of the problem is and next an obligation to inform the public," said D.C. City Council member H.R. Crawford (D-Ward 7), chairman of COG.

In proposing the conference, Crawford said that a total of 313 AIDS cases were reported in the Washington area as of June 16, with 161 resulting in death. "If this trend continues," he said, "the number of cases from the Washington metropolitan area this year will more than triple last year's total of 149 cases."

Crawford cited a need for more involvement by suburban jurisdictions, noting that 43 percent of the area cases reported to the Centers for Disease Control (CDC) in Atlanta were from suburban Maryland and Northern Virginia.

The conference on AIDS, a malady that primarily affects homosexual men, would be a forum for exchanging information and developing policies for action by local governments, according to Crawford.

*In other action, COG: Endorsed Mayor Marion Barry's plan to find jobs in the suburbs for unemployed District residents.

*Passed a resolution calling for improved safety on the Capital Beltway. The measure advocates a permanent policy of banning trucks from the left lane of the Beltway, more law officers on the road and a minimum speed limit.

*Established a committee to develop measures to further reduce noise at National Airport. The noise abatement committee would include members from area governments and nonvoting members from organized interest groups, including citizen organizations.

Area gay leaders and professionals who serve AIDS victims expressed support yesterday for the conference. Christine F. Riddiough, president of the Gertrude Stein Democratic Club, said her organization has lobbied for it.

"The number of people with AIDS increases at a rate of 40 percent every six months," she said.

"It sounds like a good idea," said Steve Smith, president of the Gay Activist Alliance. ". . . A large part of the caseload in the area is coming from the suburbs and most of the money is coming from the District."

The District government has contributed $42,000 this year to the Whitman-Walker Clinic, an AIDS treatment center in the Adams-Morgan area of the city that serves AIDS victims from all over the metropolitan area, according to David E. Rivers, director of the city's human services department.

Caitlin Ryan, program manager for the AIDS education fund at the clinic, criticized conferences held elsewhere as "too cerebral" and said some have excluded AIDS victims.

"I would want to know who their keynote speakers are and what the workshops will be," she said. "I would be interested in it only if we were involved with the planning."