State insurance commissioners chided property and casualty insurance firms yesterday for not using their economic clout to help contain soaring costs.

Harold B. McGuffey, president of the National Association of Insurance Commissioners and Kentucky's insurance commissioner, told an audience of regulators and industry representatives, "Too many members of the insurance industry view themselves only as funnels through which premiums are collected and losses paid, with no thought to controlling underment is somebody else's job - and they're wrong."

An industry that pays out $35 billion annually in claims has a responsibility to use its influence in getting better designed and safer cars, he said. And arson for profit has become a major problem because the industry is too reluctant to make a vigorous fight against false claims, McGuffey asserted.

The General Accounting Office concluded recently that FAIR plans - state-directed and federally monitored programs designed to help inner cities - are actually encouraging arson by overinsuring buildings. FAIR plans were found to provide insurance to almost everyone who requests it, regardless of character, background or prior involvment with fires.

McGuffey also charged the industry has failed to make its rate-making practices believable to the public. "Our recent experience with the medical malpractice crisis and the products liablility crisis showed us once again that insurers . . . play follow the leader, shrinking market after market and raising the prices to the point of recklessness. The public develops the attitude that the business is poorly managed or totally self-serving and greedy," he said.

He singled the driver classification system out for criticism. Insurance companies, the regulator declared, are too used to doing things the "easy" way - using age, sex and martial status of the driver as criteria. He urged insurers to use more accurate criteria such as mileage driven, number of years of driving experience, accident record and make and model of the car.

Not suprisingly, the state commissioners, who are meeting here throughout the week, oppose federal regulation of the insurance industry. Their opening session followed by one day a weekend meeting of the American Bar Association at which a Federal Trade Commission official called for changes in the McCarran-Ferguson Act, which exempts the insurance industry from federal regulations.

Amending that law would likely increase competition in the industry, said Robert Reich, director of the FTC's Office of Policy Planning and a member of its task force studying insurance.

Reich said the task force probably will urge less state regulation of insurance rates. Sixteen states now have open competition, meaning that prior approval is not required. Reich said studies, such as one done in Illinois, show that open competition benefits consumers.

However, Reich warned in his speech, "Some government intervention in the form of antitrust enforcement may be necessary to ensure that competition itself is healthy and robust." The FTC report will be incorporated into the recommendations of a panel appointed by President Carter to review federal antitrust laws.