(Adds details on specific stocks, updates prices)

* TSX up 47 points, or 0.31 percent, to 15,087.30

* Eight of the TSX's 10 main groups higher

TORONTO, Sept 12 (Reuters) - Canada's main stock index rose on Tuesday, helped by financial sector gains and moves higher in shares of Agrium Inc and Potash Corp of Saskatchewan after a competition watchdog gave their planned merger a green light.

At 9:56 a.m. ET (1356 GMT), the Toronto Stock Exchange's S&P/TSX composite index was up 47 points, or 0.31 percent, to 15,087.30. Eight of its 10 main sectors were higher.

Agrium gained 0.9 percent to C$125.43 and Potash Corp rose 1 percent to C$22.40 after Canada's Competition Bureau said it will not challenge their proposed merger.

Bombardier Inc rose 0.8 percent to C$2.43 as Britain and Canada team up to intervene in a dispute between the Canadian aircraft maker and Boeing Co.

The heavyweight financials group gained 0.3 percent, with Toronto-Dominion Bank up 0.6 percent at C$66.80 and insurer Manulife Financial Corp adding 0.5 percent to C$24.07 as Hurricane Irma appeared to have caused less damage than feared.

Energy stocks tracked oil prices slightly higher, while Nuvista Energy Ltd jumped 5.8 percent to C$6.91 after it reaffirmed its 2017 guidance.

Centerra Gold rose 0.8 percent to C$9.14, a day after saying it had reached agreement with Kyrgyzstan over its Kumtor gold mine.

The materials group, which includes precious and base metals miners and fertilizer companies, added 0.5 percent. (Reporting by Alastair Sharp; Editing by Meredith Mazzilli)