(Adds strategist's comment, details) By Alastair Sharp TORONTO, July 21 (Reuters) - Canada's main stock index retreated on Monday from its record high as a ratcheting-up of fighting in Ukraine and the Israel-Gaza conflict gave investors pause, with energy and mining stocks among the heaviest weights. Clashes broke out in the rebel-held city of Donetsk in eastern Ukraine as investigators sought access to the bodies of the victims of the Malaysian airliner shot down last week. Meanwhile, Israeli jets, tanks and artillery pounded Gaza and Palestinian militants fired rockets at Israel as the U.N. Security Council's calls for a truce were ignored. "Certainly the headline risks emanating from the geopolitical turmoil right now is dampening a little bit of investor enthusiasm," said Craig Fehr, Canadian market strategist at Edward Jones in St. Louis, Missouri. "You combine what's been going on in Ukraine for a while now with the conflict in Iraq and the invasion in Gaza, all of them, for an investor, can be put into the same pot and are somewhat worrisome." Still, Fehr said he did not expect the hostilities to dent the outlook for global growth, and he said the Toronto index should rise further in a week light on economic data, especially if bellwether North American stocks report positive earnings. Cenovus Energy Inc slipped 1 percent to C$33.08, while Canadian Natural Resources Ltd was down 0.6 percent at C$48.04. Encana Corp was off 0.8 percent at C$23.05. Canada's largest natural gas producer may sell its Deep Panuke project by the end of the year, Bloomberg reported last week. The energy and materials sectors, two of the TSX's largest, have both made significant gains so far this year. The Toronto Stock Exchange's S&P/TSX composite index was down 21.35 points, or 0.14 percent, at 15,245.22 at midmorning. It hit a record high of 15,291.15 on Friday. ($1=$1.07 Canadian) (Reporting by Alastair Sharp; Editing by Peter Galloway)