TALLAHASSEE, Fla. (AP) _ Florida's regulators are investigating whether Met Life Insurance Co. deceived thousands of policyholders _ many elderly _ to get them to buy more expensive life insurance.

Met Life is the latest company to surface as part of the state's investigation into life insurers' sales practices.

Last spring Prudential Life Insurance Co. of America, the nation's largest life insurer, agreed to pay Florida a $15 million fine to settle charges that its agents deceived 128,000 customers into buying more expensive policies with the value of current policies. John Hancock Mutual Life Insurance Co. agreed last week to pay the state $6 million and compensate up to 153,000 customers who bought policies since 1979.

``We started actively investigating Met Life and John Hancock at about the same time last spring, after the Prudential investigation was completed,'' Insurance Department spokesman Don Pride said today. ``The company, I'm told by our investigators, is cooperating fully and providing records.''

Met Life, the nation's second-largest life insurer, has about 5 percent of the life insurance market in Florida, the nation's fourth-largest state. Its among one of about a dozen targets of investigations into ``churning'' life insurance policies being conducted by Florida Insurance Commissioner Bill Nelson.

Churning is when agents coax customers into adding coverage to the already high cash value of their existing policies, saying the added coverage will cost little if anything. The agents fail to tell policyholders that the cash value of their old policies is used to pay the premiums of the new ones.

Later, customers are socked with huge, unexpected premium bills.

The accusations are similar to those against Prudential, which agreed to pay at least $410 million in restitution and $65 million in fines and other costs under a pending settlement approved by all 50 states.

New York-based Met Life also faces lawsuits in six states accusing it of breach of contract, breach of fiduciary duty and fraud.

``We deny allegations of wrongdoing and illegal activity in these cases generally,'' Met Life attorney James M. Lenaghan told The Wall Street Journal in a story published today.

The allegations come three years after Met Life paid $20 million in regulatory fines and $50 million nationwide to settle charges that its agents duped customers into buying life insurance disguised as retirement accounts.

Separately, Pennsylvania regulators fined Met Life $1.5 million in 1993 for deceptive practices in that state between 1990 and 1992.

More than 30 other insurers in the United States face suits alleging deceptive tactics, and about six recently announced settlements, the Journal said.