LOS ANGELES -- In a media merger creating the nation's third-largest newspaper company, Tribune Co. will take over Times Mirror Co. and end the dynasty that has controlled the Los Angeles Times since 1882, the Times announced today.

The $6.46 billion transaction will mark the end of Times Mirror as a company. The Chandler family, which owns a majority of the company's voting shares, initiated the deal and has pledged to approve it, the Times reported.Together, the combined companies will boast a daily newspaper circulation of 3.6 million, by the Tribune's count, including readers in the nation's three largest cities -- New York, Los Angeles and Chicago. By circulation, it will rank behind only Gannett Co. Inc. and Knight Ridder.

The deal, approved by Times Mirror directors late Sunday, still must be approved by shareholders and is subject to federal review.

It may require a waiver of Federal Communications Commission rules forbidding a company to own both a TV station and a newspaper in the same market. Tribune Co.'s broadcast holdings include KTLA-TV in Los Angeles.

Because it involved noncompetitive bidding, other bidders have 20 calendar days to top the Tribune Co.'s offer.

Under the takeover, Times Mirror shareholders will have a choice of taking $95 per share from Tribune Co. -- nearly twice the stock's recent value -- or exchanging each of their Times Mirror shares for 2.5 shares of Tribune Co. stock. The Tribune Co. also will assume about $1.4 billion in debt, the Times reported.

Tribune Co. would control operations from its Chicago headquarters, and John Madigan, chairman of Tribune Co., would head the new company, the Chicago Tribune said Monday.

Times reporters leaving work early Monday said they were surprised by the merger and uncertain about the impact.

"It's a very unsettled feeling," said Carlos Selva, a reporter with the Los Angeles Times-Washington Post news service. "As for me, I won't know until I get more details."

The proposed sale follows five years of dramatic changes at Times Mirror under the stewardship of its chief executive, Mark H. Willes. After arriving from General Mills in spring 1995, he closed The (Baltimore) Evening Sun and New York Newsday and sold off assets that substantially trimmed the company.

Wall Street rewarded those moves. The company's stock went from $23.25 in June 1995 to a high of $72.62 in November 1999. Willes pledged even more growth, particularly in the highly competitive Los Angeles market.

But over the past 18 months, circulation growth was disappointing and profits lower than expected. By Friday, the stock had fallen to $47.94, a 52-week low.

In December, the Los Angeles Times was embarrassed by the disclosure of a revenue-sharing deal with the Staples Center sports arena. Under the arrangement, the two would share advertising profits from an issue of the newspaper's Sunday magazine devoted to the arena opening.

The brunt of criticism for the deal fell on Willes' protege, Times Publisher Kathryn M. Downing, and Editor Michael Parks. Many saw it as the result of Willes' campaign to break down walls between business and news departments as a way to build the newspaper.

Willes said he will leave after the deal is completed. Downing said she does not intend to resign.

The departure of Willes and the Tribune Co.'s new leadership could help Times employees move beyond the bitterness many still feel toward management over the Staples Center controversy, Jay Christensen, an editor in the sports department, said today

"Hopefully this will put a close to that whole chapter," he said.

Willes said he was "totally surprised" when he first learned of the negotiations less than two weeks ago, since he believed the Chandler family trust prevented the paper from being sold or merged, he said.

Negotiators worked around that by giving the family four seats on an expanded 16-member board and 40 percent of the seats on the Los Angeles Times board. The Chandlers also retain certain special rights including a say in the selection of the Times publisher.

The merged companies would include 11 daily newspapers, 22 television stations and a combined market value of $11.7 billion, The New York Times reported in today's editions. --

In addition to the Los Angeles Times, Times Mirror publishes Newsday of Long Island, N.Y.; The Baltimore Sun; The Morning Call of Allentown, Pa.; and The (Stamford) Advocate, The Hartford Courant and Greenwich Time, all of Connecticut.

More than 60 million people read Times Mirror magazines, including Field & Stream, Popular Science, GOLF Magazine, Outdoor Life, SKI Magazine and SKATEboarding.

The Tribune company reported 1999 revenues of $3.2 billion and has about 13,400 employees. Tribune Broadcasting owns and operates 22 major market television stations and says it reaches more than 75 percent of U.S. television households.

The company also owns and operates four radio stations, including three stations in Denver and WGN-AM in Chicago. Tribune Entertainment, a subsidiary, develops and distributes TV programming.

In addition, the company owns the Chicago Cubs baseball team. Tribune Publishing publishes four market-leading newspapers: the Chicago Tribune, the south Florida-based Sun-Sentinel, The Orlando Sentinel of Florida and the Newport News, Va.-based Daily Press.