(Adds details throughout on stocks and sectors and updates prices)
* TSX down 203.44 points, or 1.31 percent, at 15,372.37
* All of the TSX's 10 main groups were lower
TORONTO, Jan 30 (Reuters) - Canada's main stock index fell to a nearly two-week low on Monday and was on track for its deepest loss since September after a travel ban implemented by U.S. President Donald Trump triggered uncertainty for investors.
Wall Street also lost ground after Trump on Friday signed executive orders to bar admission of Syrian refugees and suspend travel to the United States from Syria, Iraq, Iran and four other countries on the grounds of national security.
Canada will offer temporary residency to any travelers stranded by the ban.
At 11:01 a.m. ET (1601 GMT), the Toronto Stock Exchange's S&P/TSX composite index fell 203.44 points, or 1.31 percent, to 15,372.37. It last lost more than 1.3 percent on Sept. 13, while it touched its lowest intraday since Jan. 18 at 15,368.80.
Lower oil prices were an additional drag on energy stocks, with Canadian Natural Resources Ltd declining 3.9 percent to C$38.74 and the overall energy group slumping to its lowest since mid-November, down 3 percent.
The energy group got a boost last week from revived prospects for the Keystone XL pipeline, but investors have been worried about a potential U.S. border adjustment tax.
U.S. crude prices were down 1.1 percent at $52.57 a barrel as news of another weekly increase in U.S. drilling activity spread concern over rising output.
Some of the most influential weights on the TSX included the country's major bank stocks. Royal Bank of Canada fell 0.9 percent to C$93.64, while the financials group was down 1.2 percent.
All of the index's 10 main groups were lower, with industrials falling 1.4 percent and information technology sliding 1.9 percent.
The materials group, which includes precious and base metals miners and fertilizer companies, lost 0.5 percent.
Gains for gold stocks tempered losses for the materials group, with Barrick Gold Corp climbing 2.2 percent to C$23.90 as gold rose.
Gold futures rose 0.8 percent to $1,197.3 an ounce, supported by political uncertainty.
Canadian dairy company Saputo Inc said it will make an all-cash takeover offer for the 12 percent of Australia's Warrnambool Cheese and Butter it does not already own, valuing the company at A$682 million ($515 million).
Saputo's shares dipped 0.1 percent to C$48.18.
Two suspects were under arrest after a shooting at a Quebec City mosque on Sunday evening killed six people and wounded eight, but police declined to give details of their identity or possible motives. (Reporting by Fergal Smith; Editing by Tom Brown)