TORONTO (Reuters) - The Toronto Stock Exchange's main index ended flat yesterday as a surge in the price of oil and a takeover deal for Western Oil Sands Inc. offset weakness in telecoms and a plunge in Rogers Communications Inc.

The S&P/TSX composite index closed up 3.91 points at 13,868.63 with four of its 10 main sectors higher.

US crude oil futures rose toward a record high above $78 a barrel on expectations that an inventory report due today would show US crude stocks fell last week.

Toronto's oil and gas producers, which account for about 30 percent of the main index, jumped 1.5 percent as a group and represented eight of the top 10 weighted gainers yesterday.

Western Oil Sands shot up C$3.19, or 9.4 percent, to C$37.32 after Houston-based Marathon Oil Corp. said it will buy Western for about $5.56 billion, giving the US company a foothold in Alberta's lucrative oil sands.

Suncor Energy Inc. led all gainers as it announced it is seeking regulatory approval for a C$4.4 billion expansion of its oil sands mining operations. Suncor's stock climbed C$1.68, or 1.8 percent, to C$96.45.

Media and telecom company Rogers Communications led the TSX downside, battered by both its report of a second-quarter loss and comments that it is not interested in buying rival Shaw Communications Inc.

Rogers tumbled C$2.84, or 5.6 percent, to C$48.22, while Shaw slipped 88 Canadian cents, or 3.4 percent, to C$25.30.

The heavyweight financials group was up 0.2 percent as better-than-expected earnings from Sun Life Financial lifted the sector.

Sun Life reported a 15 percent rise in quarterly earnings and raised its dividend. Its stock gained C$1.34, or 2.7 percent, to C$50.39.