By Jennifer Saba

NEW YORK (Reuters) - Former New York Times publisher Arthur Ochs Sulzberger, who led the company for 34 years in a period of growth that made it a multibillion-dollar media enterprise, died on Saturday at the age of 86, the newspaper said.

Sulzberger, whose family bought the Times in 1896, died at his home in Southampton, New York, after a lengthy illness, his family said.

Sulzberger, known by his childhood nickname Punch, became publisher of the Times in 1963 and it won 31 Pulitzer Prizes under his leadership. He turned over the publishing job to his son, Arthur Sulzberger Jr., in 1992 and gave him the chairman's position in 1997.

"Punch, beloved by his colleagues, was one of our industry's most admired executives," Sulzberger Jr. said in a statement.

While he has not been active in the company for more than a decade, the elder Sulzberger's stamp on one of the world's most influential newspapers is still in place.

He helped the company achieve financial stability, started nationwide distribution, added sections that are now staples in newspapers across the country and took it public in 1969 using a duel class structure in which the family controls around 90 percent of Class B shares.

Sulzberger's grandfather Adolph S. Ochs purchased the Times in 1896 and the Ochs-Sulzbergers are one of a small group of families in the United States still serving as stewards of newspapers and media empires.

Storied newspaper names like the Pulitzers, Chandlers and Bancrofts have since exited an industry racked with challenges.

Newspapers are suffering from a drastic decline in advertising revenue and a loss of readership as people turn online and to digital products to get their news.

The passing of Sulzberger comes at a time of uncertainty for the Times. It has been selling off many of its properties and has not paid a dividend in several years. Its share price also has been slumping.

Under Sulzberger's stewardship, the New York Times became a sprawling media conglomerate with newspapers throughout the United States, magazines, television, radio and online properties.

"He was a great champion of the newsroom," said Joseph Lelyveld, executive editor of the Times from 1994-2001.

"I think the editors who had the good luck to serve him always knew on a key issue they could count on his backing if they truly believed it was a matter of great importance to the independence of the paper."

PRESS FREEDOM ISSUES

The Times won two important freedom-of-the-press fights during Sulzberger's tenure.

In 1971, the Times published the Pentagon Papers, a highly classified government history on the Vietnam War that embarrassed the administration of President Richard Nixon, which demanded the Times stop publication of the series on grounds of national security.

The Times, citing the First Amendment, refused and the U.S. Supreme Court ruled in the newspaper's favor.

"He was a mythic figure in our house - the man who defied the orders of the White House and the threat of jail to publish the Pentagon Papers," said Andrew Rosenthal, the Times' editorial page editor and son of former Times editor Abe Rosenthal.

The high court also sided with the newspaper in the Times v. Sullivan, a case that began before Sulzberger took over but was settled in 1964 when he was publisher. The ruling established standards for malice that must be proved in libel cases.

"Punch, the old Marine captain who never backed down from a fight, was an absolutely fierce defender of the freedom of the press," Sulzberger Jr. said.

In a statement from the White House, President Barack Obama said: "Over the course of more than 30 years, Arthur helped transform the New York Times and secure its status as one of the most successful and respected newspapers in the world."

Sulzberger was born in 1926, the youngest of four children of Arthur Hays Sulzberger and Iphigene Ochs Sulzberger. It was his father who coined his nickname "Punch" when he created an illustrated book involving Arthur's sister Judith.

According to the Times, his father described Arthur as having "come to play the Punch to Judy's endless show," referring to the centuries-old popular British puppet show "Punch and Judy."

Sulzberger spent nearly his entire professional life at the Times - he worked briefly for the Milwaukee Journal and served in the U.S. Marine Corps during World War Two and the Korean War. He started as a city staff reporter at the Times, working to become a foreign correspondent in the paper's Paris, Rome and London bureaus.

Despite his pedigree, his appointment to lead the company was not an obvious one, according to Gay Talese's "The Kingdom and the Power." The Times was running under the leadership of Sulzberger's brother-in-law Orvil Dryfoos, who was expected to run the paper through the 1970s.

But Dryfoos' sudden death left a vacuum at the top.

Initial concerns about Sulzberger's lack of executive experience were quickly set aside: He became the newspaper's youngest leader in its history when he was named publisher at the age of 37.

According to the Times, Sulzberger once remarked it was no coincidence that family-owned papers were among the best, quipping, "Nepotism works."

(Editing by Bill Trott and Peter Cooney)