* TSX down 161.61 points, or 1.04 percent, to 15,381.72
* Nine of TSX's 10 main groups fall
* Materials up 0.4 percent as gold prices rise
TORONTO, May 17 (Reuters) - Canada's main stock index fell on Wednesday, tracking global market concerns that U.S. President Donald Trump's pro-business economic agenda could be slowed by political scandals, with financial stocks leading declines.
The pullback in global markets came about a week after Trump fired then-FBI Director James Comey and disclosed sensitive national security information in a meeting with Russian officials.
The White House's problems worsened on Tuesday when media reported the Republican president had asked Comey in February to end a probe into his former national security adviser, a move that could be seen as obstruction of justice. The White House dismissed the reports as untrue.
The most influential movers on the Toronto Stock Exchange's S&P/TSX composite index were dominated by financial firms, which make up roughly a third of the index's weight. The group slid 1.4 percent.
Royal Bank of Canada shed 1.4 percent to C$91.745, while Toronto Dominion Bank lost 1.1 percent to C$62.41. Insurer Manulife Financial Corp dropped 3.0 percent to C$23.01.
Alternative lender Home Capital Group Inc, which reported a further decline in its deposit balances, saw shares stumble 7.0 percent to C$8.35.
At 10:30 a.m. ET (1430 GMT), the TSX fell 161.61 points, or 1.04 percent, to 15,381.72.
Eight of the index's top 10 sectors fell more than 1 percent. The materials sector, which include mining stocks, was the lone gainer, adding 0.4 percent partly on the back of higher gold prices.
Bullion hit a two-week high as the Trump scandals and weak U.S. economic data trimmed expectations the Federal Reserve would aggressively raise interest rates this year, pushing the U.S. dollar to its weakest level in six months. A weak greenback makes the precious metal cheaper for non-U.S. investors.
The bulk of the top 30 stocks that advanced were gold mining companies, with Barrick Gold Corp leading the charge. Barrick rose 2.2 percent to C$23.53, while Agnico Eagle Mines Ltd was up 2.1 percent at C$68.17. Gold futures rose 1.8 percent to $1,256.9 an ounce.
Oil and gas stocks retreated 1.0 percent despite higher crude oil prices. Enbridge Inc fell 2.2 percent to C$52.68.
Declining issues outnumbered advancing ones on the TSX by 203 to 44, for a 4.61-to-1 ratio on the downside.
The index was posting three new 52-week highs and three new 52-week lows. (Reporting by Solarina Ho; Editing by Paul Simao)