(Adds details throughout on sectors and stocks; updates prices)
* TSX falls 23.85 points, or 0.15 percent, to 16,260.36
* Eight of the index’s 10 main groups decline
* Magna International falls 1.4 percent
* Celestica declines 4.6 percent, Valeant down 4.7 percent
TORONTO, Jan 25 (Reuters) - Canada’s main stock index fell on Thursday as Magna International Inc and Valeant Pharmaceuticals International Inc weighed, offsetting gains for energy shares as oil prices rose.
* At 10:28 a.m. ET (15:28 GMT), the Toronto Stock Exchange’s S&P/TSX composite index fell 23.85 points, or 0.15 percent, to 16,260.36.
* One of the biggest drags on the index was Magna International, which fell 1.4 percent to C$72.35. The automotive supplier is among companies that could be impacted by negotiations to update the North American Free Trade Agreement.
* U.S. negotiators have held firm in their demands for a wide-ranging overhaul of NAFTA, three sources close to the talks said on Thursday, raising questions about whether any real movement is happening at the latest negotiating round on the treaty.
* Electronics manufacturing services company Celestica Inc fell 4.6 percent to C$12.99 after reporting fourth-quarter earnings after the bell on Wednesday that missed estimates.
* Valeant added to Wednesday’s sharp losses. Its shares fell 4.7 percent to C$23.37.
* The financials group, which accounts for more than one-third of the weight of the TSX, dipped 0.1 percent.
* The materials group, which includes precious and base metals miners and fertilizer companies, lost 0.4 percent.
* Eight of the index’s 10 main groups fell.
* The energy group rose 0.3 percent as oil prices climbed.
* Canadian Natural Resources Ltd gained 0.8 percent to C$44.97, while U.S. crude prices were up 1.1 percent at $66.3 a barrel. (Reporting by Fergal Smith; Editing by Meredith Mazzilli)