The decision by Chubb Corp.'s largest subsidiary, Federal Insurance Co., to switch its charter from New Jersey to Indiana because of the new insurance law in New Jersey does not pose a major threat to the state, a New Jersey state official said Wednesday.

Gregory Lawler, a counsel for policy and planning in the administration of Gov. Jim Florio, said Chubb is one of only several insurance companies that still are chartered in New Jersey.He said that the other major insurance company with a New Jersey charter, Crum & Forster, is planning to withdraw from the automobile insurance market nationwide and not particularly because of the New Jersey measure.

Chubb is not the first major insurance company to change its charter. Prudential Property and Casualty Insurance Co., known also as Prupac, switched its charter to Indiana several years ago although the company's headquarters remain in Holmdel, N.J., Mr. Lawler said.

Mr. Lawler is one of the architects of the new law, the Fair Automobile Insurance Reform Act of 1990.

Federal shifted its charter to Indiana as a result of provisions in Gov. Florio's auto insurance reform plan, the company said.

The Warren-based insurance company, chartered in New Jersey since 1901, said Tuesday it feared provisions of the new auto insurance reform would cause other states to penalize insurers chartered in New Jersey.

Bill Murray, Chubb vice president and assistant general counsel, said the action would not affect the size or the company's work force in New Jersey, the amount of state taxes it pays, the amount of business done or the location of its corporate headquarters - which will remain in New Jersey.

He said the move would prevent the new laws from causing a "significant rise" in the company's tax bill.

The Florio plan imposed $150 million in premium taxes for each of the next two years and assessments of $160 million a year for each of the next seven years on state insurers doing business in New Jersey to help close a $3.1 billion deficit amassed by the Joint Underwriting Association pool for high-risk driver.

Chubb officials are concerned that the higher taxes being imposed on out- of-state insurers doing business in New Jersey would result in retaliatory taxes against those firms chartered here that do business in other states.

"We simply want to avoid higher, retaliatory taxes," Mr. Murray said.