NEW YORK, NOV. 27 -- The Dow Jones industrial average seesawed up and down before closing the day up 10 points today, with much of the market's enthusiasm going into the stocks of smaller insurance and technology firms.

"I think pretty much everyone is already well-positioned -- where they want to be, that is -- for the end of the year," said block trader Brad Weekes at Donaldson Lufkin & Jenrette, commenting on the narrow range of trading.

Arbitrageurs, already disappointed by the $66-a-share price offered Monday by Matsushita Electric for their shares of MCA, were dealt a much nastier blow as Chairman J.L. Stead of electrical-products manufacturer Square D Co. said the company is definitely not for sale. Square D plunged 9 1/8 points to 45 3/8, a nearly 17 percent loss, after news accounts of Stead's statement. The stock has run up sharply, from near 24 in mid-October, to over 54 recently, on persistent takeover speculation.

Analyst Paul Kronlokken at Piper Jaffray & Hopwood, referring to the steep drop in Square D, said, "The only real message of the market today seems to be that it's going to be a long time before the 'takeover game' is hot again."

At the close, the Dow stood at 2543.81, up 10.64, while advances outpaced declines by a moderate ratio of nearly 2-to-1 on expanding volume of 147 million shares, compared with 131 million on Monday.

Insurance stocks were particularly strong despite rumors during the morning that Equitable Life was in financial trouble -- rumors denied both by the company and the New York state insurance commissioner. Equitable, which is owned by policy holders, is not publicly traded..

Other insurance outfits traded well. Aetna surged 2 1/8 to 39 7/8, for example, while Cigna added 1 1/4 to 39 1/4. Conseco rose another 3/4 point to 28 1/2 after a 1 3/4 rise on Monday. Chubb gained 1 1/8 to 49 3/8, Fund American rose 7/8 to 48 5/8, Progressive Corp. moved up 1 1/8 to 48 3/4, and Cincinnati Financial tacked on 2 to 81 1/2.

On the over-the-counter market, a rally in technology stocks was prompted by strong third-quarter numbers from Dell Computer. Although Dell ended the day down 1/8 at 13 in active trading, other companies posted healthy gains: Intel, up 1 1/8 to 37 1/8; Apple, up 3/4 to 37 1/2; Microsoft, up 1 5/8 to 71 7/8; Sun Microsystems, up 1 to 19 5/8.

Drug manufacturer Mylan Laboratories, up 1 1/2 at 20, benefited from favorable front-page exposure in the Wall Street Journal.

Biotech issues also advanced, with Ambegn adding 2 1/8 to close at 56 3/4 and Biogen climbing 1 1/8 to 25 1/2.

Rupert Murdoch's News Corp. gained 1 1/8 to close at 11 1/4 after announcing it had sold a 2.55 percent interest in the Reuter news service.

San Diego Gas lost 2 to close at 43 1/4 after a federal administrative law judge recommended that its merger with SCE Corp. was not in the public interest and should be blocked.

Fluor was up 5 percent, or 1 7/8, to 39 in heavy trading that the company could not explain.

The Dow transports rose 3.33 to 839.13, while the utilities eased 0.75 to 209.13 as U.S. 30-year Treasury bonds posted a quarter-point loss.

Among broad stock indexes, secondary measures performed quite well. The blue-chip Standard & Poor's 500 was up 1.59 at 318.10 and the New York Stock Exchange Composite gained 0.91 to 173.87, but secondaries were not far behind. The Value Line rose 1.66 to 230.29, the Amex Market Value gained 1.08 to 297.00 and the Nasdaq Composite surged 5.19 to 354.05.