NEW YORK, SEPT. 18 -- The stock market declined slightly today, drifting through an uneventful "triple witching hour" session.

But the drop, however modest, capped a week in which the Dow Jones industrial average posted its largest point loss in more than a year.

Dow average of 30 blue chips slipped 3.26 to 2524.64, extending its decline for the week to 84.10 points. That was its biggest weekly point decline since it fell a record 141.03 Sept. 8-12 of last year.

Volume on the New York Stock Exchange came to 188.07 million shares, up from 150.71 million Thursday.

The main event on the market agenda today was the quarterly activity involving a group of expiring stock index futures, index options and options on individual stocks.

As part of a procedure adopted in June with the aim of smoothing out the process, some contracts were settled as of the opening this morning, while others continued to be settled at the close.

Program traders closing out multiple positions in the contracts and the stocks that make up the indexes appeared to exert some upward pressure on stock prices at the outset.

In late trading, by contrast, what order imbalances showed up in reports by the Big Board were on the sell side. Prices held relatively steady, however, and overall volume wound up far below the activity seen in some past witching-hour sessions.

Brokers said the combination of the staggered settlements and close regulatory scrutiny of the markets at the witching hour apparently has put a damper on these once-frenetic occasions.

Dayton Hudson led the active list, up 5 1/8 at 58 on turnover of more than 5.4 million shares. On Thursday Dart Group proposed a friendly takeover of the company for about $65 a share.

The Gap Inc. tumbled 8 5/8 to 47 1/4 and The Limited Inc. lost 2 to 36. The two retailers, along with some others, ran into some selling after a conference Thursday on the retail-apparel industry sponsored by the brokerage firm of Smith Barney, Harris Upham & Co.

Among actively traded blue chips, Exxon rose 1/4 to 46, and General Electric picked up 1/8 to 59 7/8, while International Business Machines dropped 2 1/2 to 155 3/8.

Declining issues outnumbered advances by nearly 4 to 3 in the daily tally on the NYSE. The exchange's composite index slipped 0.12 to 176.36.

Nationwide turnover in NYSE-listed issues, including trades in those stocks on regional exchanges and in the over-the-counter market, totaled 214.98 million shares.