(Adds portfolio manager comment, updates prices to close)
* TSX ends up 63.18 points, or 0.44 percent, at 14,553.33
* Index lost 3 percent in June
TORONTO, June 30 (Reuters) - Canada's main stock index regained some ground on Tuesday after Monday's precipitous drop, with energy shares leading broad gains as crude bounced off three-week lows.
The oscillations could extend through the week amid low volumes ahead of a Greek referendum on the terms of a bailout package on Sunday, with Canadian markets closed on Wednesday and U.S. markets shut on Friday.
"We think this week is going to be really choppy," said Thane Stenner, portfolio manager with StennerZohny Investment Partners+, part of Richardson GMP. "It's going to be a tug of war between bulls and bears."
The Toronto Stock Exchange's S&P/TSX composite index ended 63.18 points, or 0.44 percent, higher at 14,553.33. It lost 3 percent in June.
The index had tumbled more than 2 percent on Monday as investors fretted about a possible Greek exit from the euro currency bloc.
"Eventually cooler heads prevail and good quality companies look cheaper after a pullback yesterday and investors come back to the markets," said Kevin Headland, director of capital markets and strategy at Manulife Asset Management.
The upside, however, looks limited, Headland said, with data on Tuesday showing the Canadian economy shrank unexpectedly in April. "Canadian economic growth prospects are muted at best," he said.
Heavily weighted gainers on the index included Suncor Energy Inc, which rose 1.8 percent to C$34.40, and Valeant Pharmaceuticals International Inc, which advanced 1.5 percent to C$277.07.
The index's energy group climbed 0.9 percent, with U.S. crude prices up 1.2 percent to $59.04 a barrel and Brent crude adding 2 percent to $63.27.
Financial shares slipped 0.1 percent, the only group to retreat. There were more than twice as many advancing shares as decliners.
The mining-heavy materials group gained 0.3 percent. Biggest weights included First Quantum Minerals Ltd, which fell 3.2 percent to C$16.33, and Teck Resources Ltd , which declined 3.7 percent to C$12.38.
Gold and copper prices both pulled back.
ProMetic Life Sciences Inc surged 16 percent to C$2.35 after it said a joint venture to manufacture biopharmaceuticals was progressing faster than anticipated.