TORONTO (Reuters) - The Toronto Stock Exchange's main index closed lower yesterday, ending four days of gains, as weak tech and financial shares dragged on the market.

The tech sector slid 2.2 percent, led down by BlackBerry maker Research In Motion, which lost C$9.07, or 8 percent, to C$104.76 after Morgan Keegan cut its rating on the stock.

Financials, which rallied last week on quarterly earnings from some of the major banks, fell 0.2 percent, hurt by profit-taking.

On the upside, Agrium Inc was among the biggest advancers by weight after the company said it will buy UAP Holding Corp for a total of $2.65 billion to create North America's largest agricultural retailer.

Agrium was up C$3.53, or 6.2 percent, at C$60.93 and helped push the materials sector up 1.2 percent.

Elsewhere in the sector, fertiliser producer Potash Corp of Saskatchewan rose C$4.62, or 3.9 percent, to C$123.42.

Toronto's key S&P/TSX composite index closed down 31.95 points, or 0.23 percent, at 13,657.17 with half of its sub-indexes lower.

The lightweight health care sector was off 2.1 percent as Biovail Corp fell 63 Canadian cents, or 4.1 percent, to C$14.58, and Cardiome Pharma Corp lost 80 Canadian cents, or 7.9 percent, to C$9.29.

A turnaround in oil prices helped the energy sector push into positive territory, up 0.4 percent. Crude rallied 60 cents to $89.31 a barrel on expectations OPEC will not up output. Suncor Energy rose C$2.77, or 2.9 percent, to C$98.38, while Petro-Canada was up 16 Canadian cents, or 0.3 percent, at C$48.46.