Urging California residents to "shop around" before purchasing homeowner insurance policies, state Insurance Commissioner John Garamendi Wednesday released a statewide survey spotlighting dramatic price differences between identical policies offered by the state's 26 largest insurance companies.

The survey also revealed major price differences between identical policies purchased in various communities and regions of California. San Diego boasted the lowest average price in the state--$439 compared to $553 in the greater Los Angeles-Orange County region. The highest prices were generally found in poorer, inner-city communities--$652 in Compton, for example.

Garamendi said the study did not deal with such provocative issues as discrimination or differences in service among insurance companies. Rather, he said, the report was intended only to make clear that consumers can benefit by comparison shopping.

"It's quite possible in Glendale to purchase a policy at twice the cost of another," said Garamendi, elected last November in the first race for the state post. "The message to consumers . . . is be a wise shopper, shop for price, shop for quality and service, but be sure to compare."

Industry spokesmen said the results were not surprising, given the varying levels of service provided by competing companies. Costs between communities vary, they said, because of such factors as crime and fire protection.

"If companies were overpricing," asserted Richard Wiebe of the American Insurance Assn., "the competitive market would insert another player into the market who would take the business."

Garamendi's survey, which also looked at renter and earthquake policies, made comparisons based on a $150,000 policy for a wood-frame home built in 1950 with a $250 deductible. Contents in the home would be insured for $75,000.

The cheapest policies across the state--averaging $412 to $420--were written by 20th Century Insurance Co., Cigna Group and CNA Insurance Cos., Garamendi said. On the top end--with prices ranging from $606 to $714--were Century-National Insurance Co., Royal Insurance Group and Chubb Group of Insurance Cos.

Of the three firms that write approximately 50% of all homeowner policies in the state, Allstate averaged $522, State Farm averaged $526 and Farmers Insurance Group averaged $555.

Garamendi said the wide range in prices reflected a lack of comparison shopping by residents across the state.