NEW YORK (AP) _ A surge in advertising revenue and new subscibers helped America Online Inc. more than triple its profit in its latest quarter, beating Wall Street expectations.

AOL earned $108.4 million, or 39 cents a diluted share, in the first quarter of its 1999 fiscal year. That was up from a profit of $31.7 million, or 13 cents a diluted share, in the year-ago quarter.

The company also said it would split its high-flying stock for the fifth time since going public 6 years ago. The two-for-one stock split takes effect Nov. 17.

The company's stock was down 56 1/4 cents at $121.43 3/4 in morning trading on the New York Stock Exchange.

Revenue grew 65 percent to $858.1 million from $521.6 million, buoyed by a 64 percent increase in advertising and other commercial revenues and higher fees from subscribers. The online service added 951,000 new subscribers in the quarter, for a total of 13.5 million, helped by the shipment of its latest online software, AOL 4.0 for Windows.

``I think it was across-the-board momentum,'' AOL chairman Steve Case said in a telephone interview.

Case added that the company had no immediate need to increase its subscriber fees after increasing its monthly $19.95 fee for unlimited access by $2 in February.