Insurance brokers say many corporations that own high-rise buildings have purchased extra liability insurance in the three months since the MGM Grand Hotel blaze that killed 84 people and injured more than 600.

Although the trend toward high-liability insurance coverage began as much as a year ago, it was the MGM Grand fire that touched off the new corporate interest in layers of protection.

"Since the publicity of the MGM fire, the trend has accelerated," said Richard O'Hara, senior vice president for casualty business coverage at Sayre & Tosco, the Los Angeles-based broker that placed a portion of MGM's coerage.

"It's a combination of the fear . . . plus the pricing," O'Hara said. "I think, if nothing else, it's going to make people aware that a high-rise business -- any business that has crowds -- is certainly subject to some kind of catastrophe."

Brokers say many firms were alarmed that the MGM Grand had only $30 million in liability insurance when flames enveloped the hotel last Nov. 21.

So far, there, have been at least 57 lawsuits against the hotel seeking more than $1 billion in damages, and MGM has been forced to pay a stiff $35 million premium for an extra $170 million in retroactive liability insurance against possible future settlements and court victories.

John McCormick, vice president at Bayly, Martin & Fay, the retail insurance broker for the MGM Grand, said interest in higher liability has been" pretty widespread."

"It's so cheap to buy excess limits at the present time, it just doesn't pay to coast along," McCormick said.

Insurance coverage on major commercial buildings is structured with several layers of coverage. The primary layer, which is the most expensive, would pay the initial claims. If claims exceed the the primary coverage, so-called "excess layers" are tapped to make payments.

Since 1978, premiums have dropped between 20 percent and 50 percent for top layers of liability insurance mainly because of added competition for new domestic underwriters and the incursion of foreign insurance underwriters.

Within the last two months, the Beverly Hills-based Hilton Hotels Corp. had increased liability coverage on its Las Vegas Hilton hotel, where a fire killed eight people and injured hundreds.