Jan 2 (Reuters) - Canada's main stock index dropped on Wednesday, the first trading session of the year, as energy shares fell on decline in oil prices pressured by rising production.
* The energy sector slipped 2.5 percent, the most among the 11 sectors in the red, as U.S. crude prices were down 1.5 percent per barrel, while Brent crude lost 1.1 percent per barrel.
* Also weighing on sentiment was worries of a global economic slowdown, following weak data from China and Europe.
* At 9:45 a.m. ET (14:45 GMT), the Toronto Stock Exchange's S&P/TSX composite index was down 139.96 points, or 0.98 percent, at 14,182.9.
* On the TSX, 20 issues were higher, while 216 issues declined for a 10.80-to-1 ratio to the downside, with total traded volume touching 13.63 million shares.
* Among gainers, Bausch Health Companies Inc rose 3.9 percent, the most on the TSX, after brokerage Piper Jaffray upgraded the stock to "overweight" from "neutral".
* Maxar Technologies Ltd fell 5.9 percent, the most on the TSX. This was followed by Norbord Inc's 5.7 percent plunge after Bank of America Merrill Lynch lowered its price target on the share.
* The most heavily traded shares by volume were Cannabis producers Aurora Cannabis and Aphria Inc.
* The TSX posted one new 52-week high and two new lows.
* Across all Canadian issues, there were one new 52-week high and 12 new lows, with total traded volume touching 24.63 million shares. (Reporting by Amy Caren Daniel in Bengaluru; Editing by James Emmanuel)