April 30 (Reuters) - Canada's main stock index was little changed on Tuesday, as an unexpected contraction of economic growth soured investor sentiment, offsetting gains in the energy sector.
* At 9:37 a.m. ET (13:37 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 5.02 points, or 0.03 percent, at 16,595.89.
* The index is on pace to rise for the fourth straight month.
* The Canadian economy unexpectedly shrank by 0.1 percent in February, pulled down in part by weakness in the mining sector and bad weather that hurt rail transport, Statistics Canada data showed.
* Underscoring weakness in railroads, Canadian National Railway Co blamed higher operating expenses due to prolonged extreme cold weather for a lower-than-expected quarterly profit. Its shares fell more than 2 percent.
* Six of the index's 11 major sectors were lower.
* Among gainers was the energy sector, which climbed 0.8 percent on the back of higher oil prices and upbeat earnings from the likes of Encana Corp and Secure Energy Service.
* U.S. crude prices were up 1.1 percent per barrel, while Brent crude added 1.2 percent.
* The heavyweight financials sector gained 0.1 percent, while the industrials sector fell 0.6 percent.
* The materials sector, which includes precious and base metals miners and fertilizer companies, added 0.3 percent.
* On the TSX, 134 issues were higher, while 94 issues declined for a 1.43-to-1 ratio favouring gainers, with traded volume touching 10.94 million shares.
* The largest percentage gainer on the TSX was Encana Corp, which rose 3.5 percent, after the oil and gas producer raised forecast for cost savings from its acquisition of Newfield Exploration, and reported a rise in quarterly adjusted profit.
* Secure Energy Services was the second best performer, which rose 3.2 percent after better-than-expected first quarter revenue.
* Capital Power Corp fell 2.9 percent, the most on the TSX, after its results. The second biggest decliner was Hexo Corp, down 2.8 percent.
* The most heavily traded shares by volume were Prometic Life Sciences Inc, Encana Corp and Hexo Corp.
* The TSX posted three new 52-week highs and no new low.
* Across all Canadian issues, there were six new 52-week highs and three new lows, with total volume touching 20.74 million shares. (Reporting by Medha Singh in Bengaluru; Editing by James Emmanuel)