A congressional subcommittee yesterday asked the country's 16 top accounting firms for sensitive data never before made public.

In a sweeping request, the legislators asked the private partnerships to reveal their fees, profits, major clients, disagreements with clients over accounting procedures, pending lawsuits and extent of liability insurance coverage, among other things.

Rep. John Dingell (D-Mich.) asked for the accountants' cooperation in providing the same type of data that public corporations must supply to regulators and stockholders in the 10-K form. He claimed in a covering letter that the information is needed by Sept. 30 to further his investigation of the adequacy of the regulatory system.

Most auditing firms' representatives contacted yesterday declined to comment because they had not received or reviewed the request.

Ken Doyle, a partner in Price Waterhouse, said his firm had suggested to Congress five or six years ago that the major companies make public certain financial disclosures. However, the American Institute for Certified Public Accountants, a trade organization, decided instead to adopt a self-regulatory system of peer review.

AICPA President Phil Chenok said yesterday that some firms voluntarily released limited financial information years ago, but discontinued the practice because no one was interested. He said, if all accounting firms were required to make complete disclosure, people would discriminate against smaller firms on the basis of size alone.

A Washington CPA, whose firm is not among the top 16, predicted that the profession would have an extremely negative reaction to the questionnaire and that few firms would comply. "I don't see what good the information would be for the public, except to point out possible conflicts of interest," he said. "Since they are all private firms, the public can't buy stock in them."

During his year-long hearings, Dingell repeatedly has questioned whether conflicts of interest -- the auditor being paid by the client who is being evaluated -- have resulted in a clean bill of health when warning flags should have been raised. The committee is investigation cases of corporate failures that followed soon after a clean bill of health had been issued.

In a statement issued yesterday, Dingell noted that the major firms, while pledging cooperation with his oversight committee, have provided very little information thus far.

The letter told accountants they could designate as confidential any information they did not want made public, and the subcomittee would consider their requests. An aide indicated that, if the companies did not cooperate, the subcommittee might seek the data in other ways, a reference to its subpoena power.