Corporate raider T. Boone Pickens Jr., in his biggest foray yet out of the oil business, yesterday offered $5.7 billion for Newmont Mining Corp., one of the nation's largest mining companies.

The $95-a-share offer sent Newmont's stock soaring to $92 a share, up $9.50 from Friday's close.

New York-based Newmont, which has interests in gold, coal, oil and gas and a variety of metals-mining operations, had no comment on the offer.

As with most of Pickens' previous takeover attempts, Wall Street analysts said it was not clear whether Pickens really wanted to take over Newmont or whether he was bluffing in an effort to force the company -- or another suitor -- to buy out his interest at a hefty profit.

Pickens, who could not be reached for comment yesterday, is said to need cash to make dividend payments to holders of shares in his company, Mesa Limited Partnership (formerly Mesa Petroleum Co.), since Mesa's natural gas operations are not particularly profitable.

Some analysts, noting that Pickens' proposal was framed as an offer to management to negotiate rather than as a tender offer to shareholders, suggested that Pickens had not yet lined up financing for a takeover of Newmont, although Pickens said in a letter to Newmont's management that "financing can be obtained on a timely basis."

"He's made a vague proposal to management... . It's not a bona fide offer yet," said Ronald Shorr, a mining analyst at Bear, Stearns and Co. Inc. "But it could turn into one."

Indeed, another analyst, William Siedenberg of Smith Barney, Harris Upham & Co. Inc., said Pickens "right now is in effect running pretty much ahead of the pack, and would be able to pretty much come out of it with the whole company."

Pickens has been stalking Newmont for several weeks, leading a group that has amassed a stake of nearly 10 percent. The group, known as Ivanhoe Partners, includes Mesa Limited Partnership, Alabama businessman John Harbert III, NRM Energy Co. of Dallas and Galactic Resources Ltd., a Vancouver gold exploration and mining company.

Although best known for his unsuccessful but generally highly profitable attempts to take over such major oil companies as Gulf Corp., Unocal Corp. and Phillips Petroleum Co., Pickens lately has chosen targets in other industries.

In recent months, Pickens has acquired small stakes in aircraft manufacturer Boeing Co. and military electronics firm Singer Co. and has said he might increase his holdings to 15 percent in each company. But analysts have said they believe that antitakeover measures taken by Boeing and Singer made Pickens' chances of taking over either company remote.

His interest in Newmont, however, has been taken much more seriously on Wall Street, in part because Ivanhoe Partners' initial stake in the company of $379 million was so much larger than Pickens' investment in the other two. In addition, analysts say there are similarities between the oil business and the mining business that might make management of a mining company a smaller leap for Pickens, who was trained as a petroleum geologist.

Yesterday's $95 bid was seen as a good one by analysts, who value Newmont at about $100 a share. Newmont's stock price has quadrupled in the past year.

Newmont's most attractive asset is said by analysts to be its 95 percent stake in a subsidiary, Newmont Gold Co., a major gold producer. Some analysts have speculated that Pickens might try to take over Newmont Mining, sell other assets to help pay for the deal, and keep Newmont Gold. On the other hand, one possible strategy that Newmont Mining could use to evade Pickens might be to spin off the gold subsidiary as a separate company, distributing its stock in it to Newmont Mining shareholders, Siedenberg said.

Pickens could run up against one significant obstacle if he tries to take over Newmont Mining without its management's consent: the 26 percent stake in the company held by Consolidated Gold Fields, a British concern that has expressed its support for Newmont's management against Pickens. Newmont would only have to line up the votes of holders of another 25 percent of the stock to defeat a tender offer by Pickens.

Analysts said that it was unlikely that Consolidated would bid for all of Newmont to counter Pickens, but they suggested it might form a partnership with other foreign mining companies to make an alternative bid.

But Siedenberg said Consolidated could decide simply to take its profits and quit -- under Pickens' offer, Consolidated's stake in Newmont would be worth about $1.7 billion.

In his letter to Newmont Chairman Gordon R. Parker, Pickens said his partnership was "willing to discuss a broad range of alternatives to Consolidated's sale of its interest, such as an exchange of its stock interest for direct ownership interests in one or more assets of Newmont or continued ownership by Consolidated of a minority interest in the company."

Pickens' letter also said he hoped Newmont's management would stay on after a takeover to help run the company. He hinted that he would take the bid directly to shareholders if management balked.

But Shorr said of Pickens: "He's serious about making money, and it could take many forms -- maybe greenmail if he could get it, maybe taking control of this company for a period of time in which he could disperse the assets... . He's been involved in many takeover attempts in the past, but I don't see those companies in Mesa Petroleum, so I find it hard to believe he really wants to take over Newmont, Singer and Boeing."