Of 21 government lawsuits filed against public accountants for alleged criminal involvement in the savings and loan crisis, more than half involve the ''Big Six'' accounting firms, the Federal Deposit Insurance Corp. said yesterday.

Total damages involved in these suits exceeds $1.5 billion, according to the FDIC.

The FDIC presented a list of the 21 cases to the House Energy subcommittee on telecommunications and finance, which is currently developing a bill that would force companies to adopt stricter internal auditing controls and require accountants to report illegal activities uncovered in audits to government regulators if the client involved refuses to correct the problems.

The suits, involving the cream of U.S. accounting firms, cast doubts on the industry's quality and integrity, officials said. ''These actions and their targets raise very substantial concerns about what kind of work auditors are doing today and about what they should be doing,'' said Rep. Edward Markey (D-Mass.), chairman of the subcommittee.

But an attorney familiar with the cases who requested anonymity said: "Generally accepted accounting is not regulatory accounting. To retrospectively say that audits should have caught all these problems misconstrues the function of what the auditors should be doing.''

Nevertheless, the FDIC has in 14 of the 21 pending cases brought charges against the country's largest accounting firms, including Coopers & Lybrand, Ernst & Young, Peat Marwick, Arthur Young, Deloitte, Haskins & Sells and Touche, Ross & Co. Deloitte and Touche have merged, as have Ernst & Whinney and Arthur Young.

The largest of the cases -- a $500 million suit alleging breach of contract and negligence in performing audits for Western Savings Association of Dallas -- was brought against Ernst & Young.

Similarly, Deloitte, Haskins & Sells is defending itself against a $250 million malpractice and negligence suit stemming from audits done in 1983 and 1984 for Sunrise Savings & Loan Association of Boynton Beach, Fla.

Touche Ross is fighting a $300 million FDIC suit alleging audit failure and negligent accounting advice in connection with work done for Beverly Hills Savings, a California S&L that joined with Beverly Hills Federal Savings Bank in December 1988.

An industry source, who requested anonymity, said all of the large cases have several points in common. Primarily, they involve audits for thrifts that made large real estate loans in which the thrifts financed all project costs and also paid for their own fees and interest.