NEW YORK, JAN. 16 -- The head of the American Stock Exchange said today that U.S. stock exchanges would strive to keep the markets open Thursday following the outbreak of war, but the exchanges will consult quickly with each other to consider brief trading suspensions to ensure that major, market-affecting news reports were adequately disseminated.

In an interview, James R. Jones, chairman and chief executive of the American Stock Exchange, said that he anticipated that the White House would act quickly to confirm or refute rumors about war developments affecting stock prices.

In trading today on stock markets, which closed the war started, the Dow Jones industrial average rose 18 points in mostly dull trading punctuated by high volume and big gains in technology issues.

A better-than-expected earnings report by Digital Equipment cut through some of the war gloom. Digital stock soared 6 5/8 to 59 3/8, and buying spilled over conspicuously into other high-technology stocks on a variety of markets: Compaq added 2 to 59 3/4; Conner Peripherals jumped 1 1/2 to 24 7/8, IBM gained 1 5/8 to 109 1/8, Cray gained 1 5/8 to 31 3/4, Hewlett-Packard added 2 1/4 to 33 1/2 and Texas Instruments closed at 40 1/2, up 1 1/2. On the over-the-counter market, Apple Computer gained 3 to 49 3/4.

Another positive for the market was marked strength in secondary issues. Such key measures as the broad-based Value Line index of 1,700 stocks and the Nasdaq composite handily outperformed blue-chip measures all day, suggesting that glamour stocks will play catch-up if a strong rally takes hold.

At the close, the Dow stood at 2508.91, up 18.32, while advances outpaced declines on the Big Board by a ratio of almost 9 to 5 on light volume of 134 million shares.

The Dow transportation index outperformed the industrials by rallying 15.16 to 917.66, but the utilities lost 1.52 to 199.63.

Among broad stock indexes, secondary measures generally outperformed primary averages. The Standard & Poor's 500 closed up 2.45 at 316.17, the NYSE Composite up 1.30 at 173.00, the Value Line up 2.15 at 233.34, the Amex Market Value up 1.28 at 298.89 and the Nasdaq Composite up a strong 7.90 at 365.20.