NEW YORK — In a surprise move that shocked and angered many in the publishing world, Viacom Inc. on Tuesday fired Richard E. Snyder, the legendary head of its Simon & Schuster publishing division.

Viacom gave no reason for Snyder's ouster, which apparently came as a surprise to the publishing executive. Snyder could not be reached for comment, but a company source attributed the dismissal to "stylistic differences."

"It's not a strategic issue, it's a question of how things should be done," the source said. "Dick's been doing this a long time, and it's easier to make a change than to teach an old dog new tricks."

During his three decades at Simon & Schuster, Snyder, 61, led the company through a series of bold acquisitions and internal expansion, building it into the largest publishing company in the country.

A tough, sometimes controversial figure known for an autocratic style but respected for injecting modern business principles into what had been a stodgy gentleman's industry, Snyder survived despite a bitter feud with his longtime boss, former Paramount Communications Inc. Chairman Martin Davis.

He is being succeeded by Jonathan Newcomb, formerly president and chief operating officer at Simon & Schuster and a self-described protege of Snyder's.

The change should squelch speculation that Viacom might sell the publishing unit to help pay down the debt from its $10-billion acquisition of Paramount earlier this year. If a sale were in the offing, Snyder might have led a management buyout, and his presence would have been reassuring to any prospective buyer.

Simon & Schuster recently completed the purchase of Macmillan Publishing Co. and has revenue of nearly $2 billion. In addition to the publishing imprint of the same name, it owns Prentice Hall, Pocket Books and the educational software firm Computer Curriculum Corp.

Although he remained publicly neutral during the fight for control of Paramount, Snyder privately favored the bid from Barry Diller's QVC Network Inc., sources said. QVC might well have spun off the publishing division, and Snyder's poor relationship with Davis--who sought the Viacom deal--may have helped push him into Diller's camp.

While Snyder had his share of enemies in the publishing business, he also gained the respect of many authors, editors and agents, as well as competitors. And they sprung to his defense Tuesday.