The largest shareholder of Walt Disney Productions has nearly doubled its stake in the embattled entertainment company, and Disney's new management team says it is "enormously pleased" by the action.

The Bass family of Texas, a group of investors worth billions, bought 2.5 million shares of Disney stock Tuesday for $150 million to raise its Disney holding to 16 percent from 8.55 percent.

The Basses' purchase cements the position of a Disney shareholder that has been generally loyal to the company through the past several months of takeover threats, management challenges and other upheavals at Disney -- although the Basses themselves at one point reportedly threatened a battle for control of the company if they did not get their way.

It was not known who had sold the stock to the Basses, who bought the bulk of it in two large blocks, but market speculation centered on arbitrager Ivan Boesky as one large seller. Boesky had purchased 1.1 million shares of Disney earlier this year in a gamble that the company would be taken over and he could sell the stock to the acquirer for a hefty profit. A spokesman for Boesky would not comment yesterday on whether Boesky had sold his stock.

It was not clear what effect the increase in the Basses' stake would have on the position of Irwin Jacobs, a Minneapolis financier who owns 7.7 percent of Disney and has threatened repeatedly to wage a battle for control of the company. Jacobs declined to comment on the Basses' action.

The Basses, who do not discuss their investments with the press, first became shareholders in Disney earlier this year, when they received a 5.5 percent stake in the company in exchange for their holdings in Arvida Corp., a Florida land development company. Disney bought Arvida to head off a threatened takeover attempt from financier Saul Steinberg, who later sold his 11 percent holding in Disney back to the company.

In the months since, the Basses have played an increasingly influential role in Disney affairs. They strongly opposed Disney's abortive attempt to purchase Gibson Greeting Co. as a defense against a takeover threat from Jacobs, and reportedly were instrumental in the ouster of Ron Miller, the Disney chief executive who had planned the Gibson acquisition.

The Basses also had a major role in picking Miller's successor, reportedly threatening a proxy fight to oust the company's board if it did not choose longtime Hollywood executives Michael D. Eisner and Frank G. Wells to run the company. Eisner and Wells were named chairman and president of Disney, respectively, last week.

A Disney spokesman said yesterday that "our management couldn't be more enthusiastic" about the Basses' stock purchase. "We consider it a strong vote of confidence from the Bass family."

The spokesman said it was not known whether the Basses, who already have one representative on Disney's board, would seek additional seats.