NEW YORK (TheStreet) -- BHP Billiton (BHP) - Get Report formally launched its offer to holders of Potash Corp. of Saskatchewan (POT) to tender their shares for $130 each in cash, or nearly $39 billion.

The offer

expires Oct. 19.

It's the same bid that

BHP took to Potash management

last week, and the same one it

went hostile with

on Wednesday.

Pictured above: an underground shaft at a Potash Corp. mine in Saskatchewan.

Potash made the obligatory press statement that its board would "review" the formal proposal and that it would at some point "make a recommendation to shareholders regarding the offer," but that, "in the meantime," it "advises shareholders not to take any action."

Also in the meantime, Potash is reportedly attempting to find another buyer -- any other buyer -- to counter BHP's bid, or at the very least to use as a form of stalking horse that would motivate a raised bid from the Australio-Anglo mining conglomerate.

The Wall Street Journal

reported late Thursday that the Saskatchewan company, the largest fertilizer producer in the world, could be

looking to China for a white knight

.

>>After Potash: 4 Fertilizer Takeover Targets

Potash's favorite phrase to describe the merits of BHP's bid is "grossly inadequate." But CEO Bill Doyle said on Tuesday, "I'm not saying that we are opposed to a sale, but what I am saying is we are opposed to a steal of the company."

Potash shares were trading lower in the early going Friday, changing hands recently at $147.42, down 1% from the prior session, when the stock gained ground even amid another sharp downdraft in the broader equities markets. Potash shares have spiked 30% since Tuesday, when the crop-nutrient giant first announced that BHP had approached it with a deal the previous week.

Clearly investors have laid their bets on BHP, or another bidder, increasing the buyout price well beyond $130 a share. Fertilizer-industry stock analysts have speculated that a deal could go down for as much as $180 a share, which would amount to $53.4 billion.

BHP has reportedly lined up loans worth $45 billion from a group of banks. The mining giant has about $8.3 billion in cash on its balance sheet, and could raise perhaps another $10 billion by selling non-core Potash assets were it to strike a deal, analyst say.

-- Written by Scott Eden in New York

RELATED STORIES:

>>After Potash: 4 Fertilizer Takeover Targets

>>Potash Goes Higher as BHP Goes Hostile

>>Will BHP Billiton Win Potash?

>>Potash-BHP Deal Seen as Inevitable

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