June 25 (Reuters) - Canada's main stock index fell on Tuesday, as heightening tensions in the Middle East and worries that the G20 meeting may yield little progress on the U.S.-China trade front kept investors on edge.
* In a dramatic and unprecedented move, Trump on Monday imposed new sanctions on Iran's supreme leader and foreign minister, a decision Tehran said closed the path to diplomacy between the countries.
* Oil prices inched about half a percent higher and helped the energy sector eke out slight gains.
* Meanwhile, investor focus will be on trade talks between the United States and China. However, hopes of a deal being reached was dampened after a senior U.S. official said President Donald Trump is "comfortable with any outcome" from the meeting.
* Nine of the 11 major sectors were trading lower, with the technology sector leading losses with a 0.9% drop.
* At 9:50 a.m. ET (13:50 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 49.33 points, or 0.3%, at 16,474.14.
* Investors will also watch for a handful of speeches from U.S. Federal Reserve policy makers, including Chairman Jerome Powell, who is facing pressure from Trump to cut interest rates in the face of a slowing economy.
* The uncertainty in markets sent investors towards safe haven bets including gold, which lifted the materials sector by 0.1%.
* On the TSX, 64 issues were higher, while 167 issues declined for a 2.61-to-1 ratio to the downside, with traded volumes touching 24.97 million shares.
* The largest percentage gainer on the TSX was Bausch Health Co, which rose 4.2% after the generic drug maker reduced its debt by $100 million.
* Bombardier Inc, which rose 4.1%, was among the top gainers after a deal to sell its money-losing regional jet business to Japan's Mitsubishi Heavy Industries Ltd for $550 million in cash.
* Among the top losers, ATS Automation Tooling Systems Inc fell 4% after TD Securities downgraded its shares to "hold". Also, Osisko Gold Royalties fell 3.9% after a secondary stock deal
* The most heavily traded shares by volume were Bombardier , B2gold Corp and Les Resources Yorbeau .
* The TSX posted 13 new 52-week highs and two new lows.
* Across all Canadian issues, there were 38 new 52-week highs and ten new lows, with total volumes touching 44.25 million shares. (Reporting by Amy Caren Daniel in Bengaluru; Editing by James Emmanuel)