(Updates prices and market activity)
* TSX rises 0.12 percent to add to previous session's record high
* Six of 10 main groups end higher
* Energy gains 0.9 percent
By Fergal Smith
TORONTO, Dec 28 (Reuters) - Canada's main stock index extended gains on Thursday from the previous session's record high as the rise in shares of energy, technology and marijuana companies offset losses for industrials and gold miners.
* The Toronto Stock Exchange's S&P/TSX composite index ended up 18.82 points, or 0.12 percent, at 16,221.95, eclipsing Wednesday's all-time closing high.
* Energy shares rose 0.9 percent, with Cenovus Energy Inc gaining 2.1 percent to C$11.58, as oil prices rose.
* U.S. crude futures settled 0.3 percent higher at $59.84 after data showed strong demand for crude imports in China and on increased U.S. refining activity that drew more crude from inventories.
* The largest percentage gainer on the TSX was Canopy Growth Co, which rose 9.5 percent to C$30.41. Gains this week for the shares of marijuana companies come ahead of the legalization of recreational marijuana in California on Jan. 1.
* Open Text Corp, rose 6.9 percent to C$44.66 after S&P Dow Jones Indices announced after the bell on Wednesday that the stock of the business software maker will be added to the S&P/TSX 60, 60 Capped and 60 Equal Weight Indices to replace Agrium Inc.
* Potash Corp of Saskatchewan Inc and Agrium have received final regulatory clearance to merge, forming a new company to be known as Nutrien, the two firms said on Wednesday.
* The materials group, which includes precious and base metals miners and fertilizer companies, dipped 0.3 percent as gold mining shares fell.
* Sandstorm Gold Ltd fell 3.8 percent to C$6.28.
* The industrials group fell 0.9 percent, including losses for railroad stocks.
* One of the biggest drags on the index was Brookfield Infrastructure Partners LP, which fell 2.0 percent to C$56.69 after rallying on Wednesday. Earlier in the week the company announced an agreement to sell its Chilean regulated transmission business for $1.3 billion.
* Six of the TSX's 10 main groups ended higher. (Reporting by Fergal Smith; Editing by David Gregorio and Diane Craft)