A group of 13 Washington hospitals filed suit yesterday in D.C. Superior Court seeking to stop the city from enforcing new regulations, developed under a federal health care program, that require reporting procedures the hospitals contend would cost them millions of dollars.

In their suit, the hospitals and the District of Columbia Hospital Association maintain that the city's new regulations go far beyond federal requirements and would impose substantial expenses at a time when they say they already are strapped for cash.

The hospitals are seeking an injunction to stop the city from enforcing the rules. They contend city officials violated administrative procedures in implementing the regulations, and that complying with the new requirements would damage their ability to compete with other health facilities by forcing them to disclose detailed information about their finances and long-range plans.

Plaintiffs in the suit include virtually all Washington's major hospitals, including Washington Hospital Center, Howard University Hospital, Children's Hospital and others.

The new regulations, contained in a 100-page document, went into effect yesterday. They are part of the city's Certificate of Need program, the mechanism established under the National Health Planning and Resources Development Act to regulate major hospital expenditures for equipment and construction.

The CON program was established in the city two years ago. An attorney for the hospitals, Guy Collier, said the hospitals until now have been satisfied with the program and its reporting requirements, which he said had been minimal.

The hospital are contesting what Collier called "copious data-reporting requirements" that apply to "every aspect of hospital operations" and would for the first time, he said, apply even to hospitals that are not contemplating what he termed major construction or equipment purchases.

The law requires, for instance, CON approval for new health services that cost $250,000 or more annually, or capital expenditures exceding $600,000. "This is just one more regulatory burden the hospitals feel they just can't afford to bear right now," Collier said.

The regulations also prescribe criminal sanctions for failure to comply with CON requirements.

Officials at the city's Department of Human Services, who maintain the CON program and developed the regulations, could not be reached for comment.