TORONTO (Bloomberg) - Canadian stocks rose for a second time in three days as Bank of Montreal averted $1.46 billion in potential writedowns on commercial paper investments, spurring a rally in financial shares from a 28-month low.

Canadian Imperial Bank of Commerce and other lenders also benefited as investors fled commodities on concern record prices for raw materials were unwarranted, given slowing US economic growth. Barrick Gold Corp. led commodity producers lower as bullion headed for its steepest weekly drop in a quarter century.

"People are trying to jump from the not-beaten up sector to the beaten-up," said Greg Eckel, who helps manage about C$1.2 billion at Toronto-based Morgan Meighen & Associates. "Nothing tempts me. The globe is still tied to the US and Canada maybe especially so. There will be a slowdown."

The Standard & Poor's/TSX Composite Index climbed 66.26, or 0.5 percent, to 12,775.64 in Toronto after dropping as much as two percent earlier. The benchmark still lost 3.6 percent this four-day week on declines among commodity shares, which account for almost half the market's value.

Canadian financial markets were closed for the Good Friday holiday. The S&P/TSX is 13 percent below an October 31 peak.

Bank of Montreal rose C$2.41, or 5.7 percent, to C$44.51, for a three-day gain of 14 percent, the best in more than nine years. Canada's fourth-biggest bank said on Thursday that it boosted its investment in Apex and Sitka trusts to C$815 million and that it will offer C$850 million in funding to satisfy collateral calls.

The risk of a loss is "low" and further writedowns on the trusts are not expected, Bank of Montreal said.

The stock has still lost one fifth of its value this year as Canadian lenders racked up about $6.6 billion in writedowns and losses on investments tied to the US mortgage market.

Smaller rival Canadian Imperial added C$4.09, or 6.8 percent, to C$64.26, the most in more than five years.

National Bank of Canada rose C$3.18, or 7.1 percent, to C$48.18, the biggest gain since November 28. The country's sixth- largest bank, which has the most at stake among Canadian lenders in asset-backed commercial paper, said this week that it will contribute about C$815 million to support the restructuring of a portion of the market that's been frozen since last August.

Research In Motion Ltd. rose C$4.50, or 4.4 percent, to C$107.07. The maker of the BlackBerry e-mail phones rose along with shares of finance companies, which are among the biggest customers for its devices.

A measure of financial shares added 2.1 percent, pushing it to its first weekly gain in a month. It has still lost 13 percent of its value in 2008.

"I'm going to need longer to increase my comfort levels," Mr. Eckel said. "I don't know whether this is the start of a rally or a bounce in a bear market. I'm prepared to miss the first 10 percent."

Commodity prices plunged, heading for the biggest weekly decline in more than 50 years, on speculation a slowing global economy will curb demand for energy, metals and grains. The Reuters/Jefferies CRB Index of 19 commodities has tumbled 8.3 percent this week. Gold slid eight percent this week, while crude oil tumbled 6.3 percent.

Energy, metals and fertilizers make up more than half of Canada's exports, of which about three-quarters go to the US, the nation's biggest trading partner.

Canada's economy will shrink this quarter, Toronto-Dominion Bank forecast yesterday citing the effects of a worsening slowdown in the US. The bank lowered its growth forecast for 2008 to 1.1 percent from two percent saying that the slowing US, coupled with a strong Canadian currency, will cause a 3.7 percent drop in exports this year.

Barrick Gold, the largest bullion miner, retreated C$2.98 to C$42.98, and 18 percent this week. Goldcorp Inc., the second- biggest producer of the metal by market value, fell C$1.32 to C$38.18, down 15 percent for the week. Smaller rival Kinross Gold Inc. added seven cent to C$22.37, paring its weekly loss to 16 percent.

Potash Corp. of Saskatchewan Inc. added 52 cents to C$147.57. The biggest maker of crop nutrients was raised to "sector outperform" from "sector perform" by CIBC World Markets analyst Jacob Bout, who increased his share-price target to C$204.56 ($200) from C$158.75. Potash pared its decline this week to 6.7 percent. The stock has more than doubled in a year.

A gauge of raw-materials companies slid 1.7 percent, taking its weekly loss to 11 percent. It is up 2.8 percent in 2008, the only one among 10 industry groups in the S&P/TSX to have risen.

An index of energy producers fell 0.2 percent on Thursday.

Suncor Energy Inc., the second-largest oil-sands miner, fell 98 cents to C$95.96, for a weekly slide of eight percent. Canadian Natural Resources Ltd., the nation's second-biggest gas producer, fell 39 cents to C$66.41, down 8.7 percent for the week.