TORONTO (Bloomberg) - Canadian stocks rose, sending the main index to its biggest gain since March, as energy producers climbed with oil prices and Citigroup Inc. analysts predicted Research In Motion Ltd. will increase its profit forecast.

Canadian Natural Resources Ltd. and EnCana Corp. led a group of energy stocks to its steepest advance in two years. Research In Motion climbed a second day after Citigroup analysts said the Blackberry e-mail phone maker will beat earnings estimates because of new products and the company's "superior" business model.

Research In Motion is "a company that's well watched by the market and it looks good to us," said Douglas Davis, who oversees about $460 million as president of Davis-Rea Ltd. in Toronto. "It's had a good run-up lately, but the five-year prospects of the company are even better."

The Standard & Poor's/TSX Composite Index rose the most since March 25, adding two percent to 14,982.91. The measure is up 8.3 percent this year.

Canadian Natural Resources, the developer of a C$8.7 billion ($8.55 billion) oil-sands project, gained 6.4 percent to C$103.64 and contributed the most to today's advance. EnCana, Canada's largest natural-gas producer, rose 3.6 percent to C$92.43.

Energy shares increased 3.5 percent, the steepest gain since June 2006. Oil rose more than $5 as the dollar dropped against the euro on statements that the European Central Bank may boost interest rates to cut inflation.

Research In Motion gained one percent to C$137.77 and helped push a group of technology stocks 0.9 percent higher. The stock, which has risen 22 percent this year, makes up 83 percent of the eight-member industry group.

Analysts polled by Bloomberg anticipate Research In Motion will say it earned 85 cents a share, on average, when it releases quarterly results on June 25.

MDS Inc. had the biggest drop since 2001, losing 9.1 percent to C$16.90. The decline was the steepest in the S&P/TSX and sent a gauge of health-care stocks down 2.3 percent.

The maker of medical devices and software cut its earnings forecast for the year because of "softening demand" for equipment used in the pharmaceutical industry and a delay in reaching "targeted profitability" in the contract-research division.

The company expects adjusted earnings of 27 cents to 33 cents a share for the year, according to a PR Newswire statement. On February 21, MDS forecast earnings of 37 cents to 43 cents.