BOSTON ( TheStreet) -- The following are three ratings changes from TheStreet's stock model.

3. The model upgraded home-products seller Williams-Sonoma ( WSM) to "buy." Williams-Sonoma operates the Williams-Sonoma and Pottery Barn stores and sells directly to consumers through its magazines and e-commerce sites.

Quarter: Fiscal fourth-quarter profit rose six-fold to $88 million, or 81 cents a share, as revenue grew 8.1% to $1.1 billion. The operating margin expanded from 3.2% to 13%. Williams-Sonoma holds $514 million of cash and $10 million of debt.

Stock: Williams-Sonoma has surged 139% in the past year, outperforming U.S. indices. The stock trades at a PEG ratio, a measure of value relative to expected growth, of 0.8, a discount to its peer-group average. A PEG ratio below 1 implies a bargain.

Consensus: Of analysts covering Williams-Sonoma, two advise purchasing its shares, 18 recommend holding and three suggest selling them. Sterne, Agee & Leach projects a share price of $32, leaving a potential 20% gain in the weeks ahead.

2. The model downgraded Baytex Energy Trust ( BTE) to "hold." Baytex is an investment trust that acquires oil and gas deposits in Canada. It plans to convert to a corporation by the end of 2010 due to a change in Canada's trust taxation.

Quarter: Fourth-quarter profit tumbled 47% to $28 million, or 25 cents, as revenue climbed 17% to $198 million. The operating margin jumped from 2.8% to 13%. Baytex's balance sheet contains $10 million of cash and $423 million of debt.

Stock: Baytex Energy Trust has soared 176% during the past 12 months, beating major benchmarks. The stock sells for a price-to-sales ratio of 5.8, a 42% discount to the industry average. It's costly based on trailing earnings and cash flow.

Consensus: Of researchers evaluating Baytex Energy Trust, seven, or 64%, rate its stock "buy, three rate it "hold" and one ranks it "sell." Macquarie expects the stock to advance 12% to $39.28. Raymond James believes it will outperform peers.

1. The model upgraded Tiffany & Co. ( TIF) to "buy." Tiffany designs, manufactures and retails jewelry through its stores, catalog and the Internet. During the past three years, the company has increased revenue 1.9% annually, on average.

Quarter: Fiscal fourth-quarter profit quadrupled to $140 million, or $1.09, as revenue increased 17% to $981 million. The operating margin remained steady at 23%. Tiffany's balance sheet stores $786 million of cash and $754 million of debt.

Stock: Tiffany & Co. has doubled in the past year, outpacing U.S. indices. The stock trades at a price-to-projected-earnings ratio of 17 and a price-to-book ratio of 3.1, on par with competitors' shares. It's expensive based on sales and cash flow.

Consensus: Of firms following Tiffany & Co., 14, or 70%, recommend purchasing its shares and six counsel holding them. Caris & Co. expects the stock to hit $58, implying a potential 21% return. KeyBanc Securities and Jefferies also rate it "buy."

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