NEW YORK, AUG. 17 -- The Dow Jones industrial average today closed above the 2700 mark for the first time, completing the fastest 100-point advance in its history. It was the Dow's 50th record close this year.

The Dow gained 15.14 points to finish at 2700.57.

The closely watched average closed above 2600 for the first time just seven days ago, on Aug. 10. The old record for a 100-point jump was 11 days, when it rose from 2000 to a close of 2100 on Jan. 19.

Today's milestone advance was set up by last week's record gain of 93.43 points. The average made three moves past 2700 late last week and earlier today, but fell back quickly on profit taking each time.

Today's record close came in a narrowly based rally that left most stocks little changed.

"The market kept edging up and at the closing bell passed 2700 -- that is a very, very bullish development," said trader John Havens of Morgan Stanley Inc. "We will have to see what happens overnight in foreign markets, but I think this sets the stage for another big gain tomorrow."

News last week of a wider U.S. trade deficit had dampened optimism over the economy and put pressure on the dollar since Friday's close.

But oil prices plunged to below $20 a barrel today over concerns about excess supply, which eased investors' concerns about inflation. That, plus a series of takeover developments, added enough support to trigger the narrow rally.

The New York Stock Exchange composite index rose 0.07 to 186.76, and declines led advances 823 to 774.

Big Board volume fell to 166 million shares from 196 million Friday.

The Standard and Poor's 500 rose 0.12, to 334.11. The Amex index fell 0.74, to 362.87, while the Nasdaq over-the-counter index gained 0.04 to 451.65.

The takeover developments provided a cushion for the market. The leading gainer in takeover-related stocks, the electronics concern ADT Inc., jumped 14 3/8 to 48 5/8 after news that Hawley Group PLC of Britain has offered to take over the company at $47 per share.

Gillette was the most active NYSE-listed issue, rising 3 to 43 1/2. It received a $47-a-share bid from Revlon Group.

Profit taking created an uphill struggle throughout the session as some investors decided to cash in gains after a rise of nearly 500 points since the low in mid-May.

But blue chips shrugged off the pressures, led by Merck, which climbed 3 3/8 to 207 3/4.

"The game in town is still the game of quality," said Peter Furniss of Smith Barney, Harris Upham. "People realize that if the nondomestic investor continues to buy our market and push it up, he is likely going to continue to go after the proven leaders and the big names -- the blue chips."

"It proves once again that this market does not want to give up any ground, and sensing that, people felt they don't want to be left out," said another trader