TORONTO (Reuters) - Gains on the Toronto Stock Exchange fizzled out yesterday, sending the main index slightly lower on profit-taking, following a strong run-up spurred by record high oil prices.

The energy sector, which earlier rose by as much as 1.4 percent, finished up just 0.2 percent as crude eased back from yet another new high near $120 a barrel in the wake of supply outages.

On Bay Street, the group was mixed, with Petro-Canada up 81 Canadian cents, or 1.6 percent, at C$50.13, while Suncor Energy was down C$1.77, or 1.5 percent, at C$115.50.

Also in the oil patch, Synenco Energy climbed C$1.18, or 15.2 percent, to C$8.97 after French oil major Total said it had agreed to buy the Canadian company for about C$480 million.

The S&P/TSX composite index closed down 18.02 points, or 0.13 percent, at 14,085.85 but the resource-laden materials sector was the only group on the downside. The benchmark had gained more than 100 points earlier in the day.

Analysts said investors were taking the opportunity to consolidate positions and lock in some profit, particularly after the nearly 140-point gain the index saw on Friday.

"Some of these things have been so strong, that the temptation is there to lock in some profits," said Fred Ketchen, director of equity trading at ScotiaMcLeod.

Fertilizer companies Potash Corp of Saskatchewan and Agrium were among the biggest decliners by weight, falling C$14.80, or 7 percent, to C$195.60, and C$5.94, or 6.6 percent, to C$84.36 respectively.

Shares of both companies have surged recently, particularly Potash Corp, which reported last week its first-quarter profit nearly tripled and upped its outlook for the rest of the year amid soaring demand and prices for fertilizer.

The declines stung the overall materials sector, which fell three percent. The group was also weighed down by losses in the gold producers subindex, which gave up 1.6 percent.

Agnico-Eagle Mines was down C$1.54, or 2.4 percent, at C$61.81, while Goldcorp lost 87 Canadian cents, or 2.3 percent, to C$36.47.