NEW YORK, SEPT. 14 -- The stock market eked out its fourth straight gain today in a sluggish follow-through to last week's rally.

The Dow Jones average of 30 industrials, up more than 15 points in early trading, finished with a 4.30 gain at 2613.04.

Volume on the New York Stock Exchange slowed to 154.38 million shares from 178.02 million Friday.

Stocks advanced at the outset as bond prices rose, putting yields on the longest maturities of Treasury bonds in the 9.4 percent to 9.5 percent range, down from recent highs above 9.7 percent.

As the session passed, however, bonds gave up most of their early gains, and stocks ran into selling by traders worried that the pullback in stocks that began late last month had not yet run its course.

Historically, said analyst Newton Zinder at E.F. Hutton & Co., a gain in the Dow in the week after Labor Day indicates that the odds favor a still-higher level for the average 30 days later.

"This indicator has a good record, but did have a big miss last year," he said in his daily market commentary. "So don't mortgage the homestead based on this indicator, or any other one for that matter."

RJR Nabisco dropped 1 to 66 3/4 after trading as high as 69 5/8 as the company confirmed talk that it was developing a type of cigarette that is consumed by means of heating tobacco rather than burning it.

The stock rose strongly last week as reports of the "smokeless" innovation circulated, and brokers said some traders took profits when the news became official.

Among other actively traded blue chips, International Business Machines rose 7/8 to 162, and American Express gained 3/4 to 38, while American Telephone & Telegraph slipped 1/8 to 32 7/8.

Telex tumbled 13 1/2 to 51 7/8. The company said that its revenues and earnings for the quarter ending Sept. 30 will fall short of expectations, and that its earnings for the year will be about flat.

HAL Inc., traded on the American Stock Exchange, jumped 15 5/8 to 46 1/8. Hemmeter Corp. of Honolulu said it plans to acquire HAL, the parent company of Hawaiian Airlines, for $50 a share.

Advancing issues outnumbered declines by about 8 to 7 on the NYSE. The exchange's composite index gained 0.52 to 180.54.

Nationwide turnover in NYSE-listed issues, including trades in those stocks on regional exchanges and in the over-the-counter market, totaled 178.24 million shares.

Standard & Poor's index of 400 industrials rose 1.05 to 378.12, and S&P's 500-stock composite index was up 1.10 at 323.08.

The Nasdaq composite index for the over-the-counter market dipped 0.68 to 445.49. At the Amex, the market value index closed at 355.19, up 0.22