The District government is expected to offer an estimated $200,000 in additional financial support to the Whitman-Walker Clinic, a major AIDS service organization in the region that has been hit with steep and potentially debilitating increases in employee health insurance costs.

Clinic and city officials said yesterday that a recommendation for such assistance, which would be provided by renegotiating one of the city's eight contracts with the clinic, has been sent to Department of Human Services Director N. Anthony Calhoun for his approval.

The clinic's insurance premiums have increased every six months, rising from $142 per employee per month in January 1989 to $600, effective July 1. Whitman-Walker officials and the insurance company, Blue Cross/Blue Shield, attributed the increases to high use of the health plan by employees, several of whom are infected with the AIDS virus.

The clinic's administrator, Jim Graham, warned at a news conference yesterday that Whitman-Walker, a nonprofit facility at 1407 S St. NW, might have to curtail services or close unless something is done to ease health insurance costs for the 90 full-time employees.

"The impact of these rate increases could be devastating to the AIDS response in this city," Graham said. "They could very well force us to shut down the AIDS programs that serve thousands of people with direct medical care, financial support, housing and prevention campaigns."

The renegotiated contract, if approved, would provide money to pay the clinic's increased costs for insuring 45 employees who provide contract services to the District. The increase is expected to total about $200,000, according to sources, and will be paid out of the city's $5 million AIDS services appropriation.

The clinic must still pay premium increases for the remainder of its staff, and all clinic employees are still be responsible for paying 10 percent -- $60 a month per employee -- of their insurance costs.

Steven Sieverts, vice president for health care finance for Blue Cross/Blue Shield of the National Capital Area, said the rate increases were necessary because of the clinic's medical claims history and because of the rising costs of health insurance in general. He said the expense last year of treating just two of Whitman-Walker's employees exceeded the total premium expenses for the clinic's coverage group.

Graham said the clinic's insurance bill for July -- a 49 percent increase from six months ago -- will total $53,000. Family rates, which will rise to $1,470 next month, have gotten so prohibitive, he said, that the clinic in recent months has been unable to hire any job applicant who would need family coverage.

Graham urged the city to allow clinic workers to join D.C. government employee health plans. D.C. Council members John A. Wilson (D-Ward 2) and Betty Ann Kane (D-At Large) said they are working with the clinic on the problem of rising insurance costs.

Whitman-Walker has an annual budget of $6 million.

About half of that money comes from contracts with local governments, with the rest raised through private contributions.

Last year, the clinic had more than 6,300 patient visits to its medical unit and handled nearly 1,000 social services cases, including legal services.