(Potash story updated with stock price movement and further detail from the company's earnings report.)SASKATOON, Saskatchewan ( TheStreet) -- Potash Corp. ( POT) surpassed Wall Street estimates for the fourth quarter as profit more than doubled amid a boom in agricultural commodities. The fertilizer giant, which spent millions to fight off a hostile takeover effort by BHP Billion ( BHP) during the final period of 2010, had supremely optimistic words for the prospects of the potash business. The pronouncements from Saskatoon gave the company's stock a lift Thursday. It was changing hands recently at $175.61, up 4% from the close in the previous session. For specific financial guidance, the company lifted its projections, though the ranges were wide. Potash said it expects first-quarter profit between $2.10 and $2.70 a share (before the 3-for-1 stock split the company announced Wednesday), and full-year profit of between $8.40 and $9.60 a share. In late October, as Potash strove to fight off BHP, the Canadian fertilizer giant issued 2011 profit guidance of $8 to $8.75 a share. The current consensus targets, according to surveys of sell-side Wall Street analysts, were within those ranges: $2.24 a share for the first quarter and $8.89 a share for the full year. The company said it expects global shipments of potash to reach 55 million metric tons to 60 million metric tons in 2011, up from 52 million tons in 2010. "With global food demand as the powerful engine, we believe we have moved into the next stage of growth for our business," Potash CEO Bill Doyle enthused in his prepared statement. "Our company stands poised to capitalize on that growth and we believe our fourth-quarter results provide a glimpse of the capabilities and earning potential of our expanding world-class operations." As for the fourth quarter, Potash earned $482 million, or $1.61 a share. Excluding the more than $64 million it spent on investment bankers and lawyers in its effort to fend off BHP, the company would have earned $1.77 a share, besting analysts' estimates of $1.65. Potash also spent $2 billion to buy back shares at an average price of $142 apiece. A year ago, Potash posted a profit of about $240 million, or 80 cents a share.