Jeweler Sues Insurer for $5 Million : Lawsuit: Store in Fashion Island contends it was underpaid for the loss of stolen merchandise and lost business after a daring 1990 armed robbery.

Moboco Fine Jewelry & Gems, the victim of a spectacular robbery almost four years ago, has sued its insurance company for more than $5 million.

The Newport Beach jeweler contends that Fireman’s Fund Insurance Co. willfully prolonged its investigation of the crime and paid $5 million less than the value of the stolen merchandise and lost business.

Fireman’s settlement payment, for an undisclosed amount, came in May--more than three years after the March, 1990, robbery in which three masked men armed with assault rifles raided the store during business hours and carried away gems and antique jewelry.

The insurance company’s lawyer did not respond to a request Wednesday for an interview.

The robbery was one of two within five months at the Fashion Island shopping center. Four men were arrested in connection with the crimes, which police said stood out because of the theatrics and efficiency of the gunmen and the value of the goods taken.

The first robbery, at Carol Klein Fine Jewelry in October, 1989, netted $6 million in jewelry, police said. Each robbery took less than two minutes.

Moboco’s lawsuit, which was filed Dec. 20 in Orange County Superior Court in Santa Ana, contends that the store’s loss extended well beyond the nearly $3 million value of the gems and antique pieces. No more than 10 stolen items were recovered by 1991, according to police.

For at least a year afterward, the store lost business because it could not satisfy customer demand for the unique items it had collected over many years, said Moboco’s lawyer, Marc W. Rappel of Latham & Watkins in Los Angeles.

Also, Moboco said it lost business for at least a year because people were afraid to come into the store, Rappel said.

Fireman’s Fund had determined that Moboco’s reduced business lasted for only five months after the robbery, according to the suit.