Insurance rating agency A.M. Best Co. put Prudential Insurance Co. of America, Newark, under review while it assesses the impact of a settlement Prudential's securities unit made with the Securities and Exchange Commission to compensate investors who claimed they were misled by the brokerage.

Investors charged they were not informed of the high risks of investing in risky limited partnerships in oil and gas wells, real estate, aircraft leasing and horse breeding. Prudential Securities Inc. agreed in October to pay a minimum $371 million to more than 100,000 investors whose claims are not being pursued through other litigation or arbitration. Twice that number of investors have already settled their claims against Prudential Securities.One lawsuit filed last month charged wholesale fraud in the way Prudential Securities marketed all limited partnerships during the 1980s, according to the Chicago Tribune.

Best officials said they were also concerned that allegations of Prudential employees using improper tactics to lure investors into Prudential Property Investments Separate Account (Prisa) - a real estate fund for institutional investors - will disrupt the insurer's institutional pension fund operation. The rating agency was also concerned about catastrophe risks in Prudential's property and casualty business.

"In the next several weeks, we will continue our discussions with senior management of The Prudential regarding financial and operational implications and uncertainties related to the limited partnership scandal and Prisa," Best officials said.

Joe Vecchione, a spokesman for Prudential, said Friday the nation's largest life insurance company wasn't surprised by Best's action. Prudential officials ''will cooperate with the Best review," he said.

But, "we expect to demonstrate to Best that Prudential is as financially strong today than it was when Best last affirmed our 'A++' (superior) rating."

Mr. Vecchione said Prudential has said it has set aside reserves equivalent to its $371 million limited partnership settlement.

On top of that, the insurer intends to add about $1 billion in statutory capital this year, he said, bringing its capital cushion against sudden losses and claims to $10.8 billion.

Prudential said it has seen little evidence of lost market share from the scandal and said Prudential Securities expects to report strong earnings this year.

"We expect strong results in our insurance operations and from our affiliates including Prudential Securities," Mr. Vecchione said.

Meanwhile, New Jersey Insurance regulators are close to completing their own examination of Prudential that began in 1992. The Prudential examination is a routine review made of all New Jersey insurance companies every five years, said Pete Cammarano, a spokesman for the department.

He would not comment on Best's action except to say "we're monitoring the situation."

Competing insurance rating agency Standard and Poor's Corp. had not changed its claims-paying ability rating of Prudential as of last Friday. The rating stood at "AA+," which officials assigned to Prudential in November 1992 and affirmed on Nov. 15.

One week after S&P affirmed Prudential's rating officials announced that Prudential Securities wouldn't need its parent to pay claims resulting from settlement of federal and state charges using improper sales tactics. At that time, Prudential Spokesman Tim Biggs said Prudential Securities had a $700 million reserve fund to draw on.