William F. Thomas, an editor who led the Los Angeles Times during an extraordinary period of expansion in the 1970s and 1980s, when the paper widened its reach nationally and abroad and became a showcase for literary journalism, died Feb. 23 at his home in Los Angeles. He was 89.

His son Pete Thomas confirmed the death. The cause was not reported.

Mr. Thomas helped the Los Angeles Times reap 11 Pulitzer Prizes during his three-decade career at the newspaper.

“He was perhaps the least well known of any editor of any major newspaper,” said former Times publisher and CNN president Tom Johnson. “He never sought the spotlight for himself. His passion was for great writing.”

Mr. Thomas led the Times from 1971 to 1989 and oversaw the launch of the Sunday magazine, Book Review and daily Business and Calendar sections; opened 11 domestic and foreign bureaus; and started regional editions in San Diego and the San Fernando Valley.

Los Angeles Times editor Bill Thomas in 1982. (Los Angeles Times)

With these steps, he pursued publisher Otis Chandler’s ambition of putting the Los Angeles Times on the level of its more established rivals, the New York Times and The Washington Post.

Mr. Thomas emphasized originality in reporting and writing. Often the subjects were esoteric — conjoined twins in Los Angeles, exotic commerce on the Congo River, the rugged world of commodities traders in Chicago — and took months of research, but the results were probing, stylish stories that often ran at great length.

Alongside breaking news and investigative reports, “there were a couple of stories in the paper every day that you might have found . . . only in the New Yorker or a handful of other places, that were beautifully written, deeply reported, full of insight,” said Tom Rosenstiel, a media reporter during Mr. Thomas’s years who now directs the nonprofit American Press Institute in Reston, Va.

In an age increasingly dominated by television, Mr. Thomas believed that newspapers had to break with rigid formulas of the past — “the stiff-necked approach to news,” he once called it. He was not a fan of market research and instead championed stories he personally found interesting or important.

His Times had detractors, including some inside Mr. Thomas’s own newsroom. Editors at rival newspapers began to emphasize punchy local stories that they said the Times ignored in its rush to become nationally respected and journalistically different.

One of these stories concerned Eulia Love, a South Los Angeles woman who was shot to death by police officers in a 1979 confrontation over an unpaid $22 gas bill. The Los Angeles Herald Examiner made the shooting front-page news, but the Times at first buried it.

The criticism that the Times ignored or was slow to cover major stories in its own backyard was ironic, given Mr. Thomas’s background in local news.

Mr. Thomas was born in Bay City, Mich., on June 11, 1924, the son of a bank vice president. Mr. Thomas was a World War II veteran, earned bachelor’s and master’s degrees in journalism from Northwestern University in Evanston, Ill., and worked at newspapers in Buffalo and in the Los Angeles suburbs before becoming editor, in 1957, of the Los Angeles Mirror, an afternoon paper owned by the Chandler family. When the Mirror closed in 1962, Chandler, who had become publisher of the Times two years earlier, brought Mr. Thomas to the larger morning paper.

He became assistant city editor in 1962 and metropolitan editor in 1965, just before the biggest local story of the year erupted — the Watts riots.

The Times’ coverage of the riots brought the paper’s first Pulitzer for local reporting, in 1966. It was one of two local Pulitzers the paper would win while Mr. Thomas was metro editor.

He recruited talented writers from underground and alternative papers as well as mainstream dailies and gave them creative license. The paper became a showcase for gifted journalists such as Dave Smith, Charles T. Powers and Bella Stumbo, whose dogged reporting and compelling narrative styles set new standards for the paper.

There was nothing flamboyant about Mr. Thomas, however. He lacked the combative personality of New York Times editor A.M. Rosenthal. He wasn’t played by Jason Robards in a movie, as was The Post’s Benjamin C. Bradlee. Yet Mr. Thomas was a man of some complexity, confident and decisive but also so shy and private that some staffers nicknamed him “invisi-Bill.”

He was not Chandler’s first choice when the publisher considered candidates to succeed editor Nick B. Williams.

The heir apparent was Robert J. Donovan, the paper’s former Washington bureau chief, but he rubbed some people the wrong way and didn’t know Los Angeles.

Mr. Thomas, on the other hand, “knew the city and the greater community far better than any of the Easterners,” David Halberstam observed in his classic media study “The Powers That Be.” “He was very smart and very ambitious and yet he was never contentious.”

Under Mr. Thomas’s leadership, the Times won more Pulitzers than it had in the preceding eight decades. One was the gold medal for meritorious public service for a series on Southern California’s burgeoning Latino community, awarded in 1984.

Mr. Thomas, The Post’s Bradlee said later, had presided over the Times “at a time when it became a great American newspaper.”

During his 27 years at the Times, Mr. Thomas saw dramatic changes, including a rise in daily circulation from 757,000 in 1962 to more than 1.1 million in 1989, when he retired.

By then, the climate for “a special kind of journalism” — the slogan for a long-running advertising campaign touting the Times’ literary aspirations — had begun to deteriorate.

During the 1990s and 2000s, his successors battled with cost-conscious publishers who were not named Chandler and began to preach limits — something Mr. Thomas had not known during the golden years of expansion under Otis Chandler.

There was no way back to that era, when print journalism still ruled and a determined editor such as Mr. Thomas could, as he once told Los Angeles magazine, “put out the paper we wanted to put out, with few restraints and lots of encouragement.”

“My style was to do the job and push the boundaries,” Mr. Thomas reflected in 2006, when Chandler died, “and once Otis realized I knew what I was doing, he let me do it.”

His wife, Pat, whom he married in 1948, died in 2000. Survivors include three sons and a granddaughter.

— Los Angeles Times