* TSX down 30.35 points, or 0.20 percent, at 15,525.74 * Five of 10 main index sectors decline * Energy shares slip with oil price By John Tilak TORONTO, Aug 22 (Reuters) - Canada's main stock index slipped on Friday in a choppy market after U.S. Federal Reserve Chair Janet Yellen called for a "pragmatic" approach that gives the central bank the flexibility to determine next steps based on evolving economic data. In a speech to policymakers, Yellen said that U.S. labor markets remained hampered by the effects of the Great Recession and the Fed should move cautiously in determining when interest rates should rise. Another factor playing into the market was worries about a further escalation of tensions in Ukraine, which said Russia had launched a "direct invasion" of its territory after Moscow sent a convoy of aid trucks across the border. The benchmark Canadian index has been climbing steadily in recent months and is up about 14 percent since the start of the year. It hit a record high earlier in the session on Friday before pulling back. "Yellen has come out fairly middle-of-the-road. I don't think she was quite as outright dovish as the Street would have liked," said Colin Cieszynski, chief market strategist at CMC Markets Canada. He said investors should expect increased levels of volatility as the uncertainty about Fed policy continued and geopolitical tensions weighed. "We may see markets struggle to find direction in the coming sessions," he added. "You may see a lot of back-and-forth trading as people tried to figure out what's going on." The Toronto Stock Exchange's S&P/TSX composite index was down 30.35 points, or 0.20 percent, at 15,525.74. Five of the 10 main sectors on the index were in the red. Financials, the index's most heavily weighted sector, declined 0.3 percent, with Royal Bank of Canada falling 0.9 percent to C$80.92 and Toronto Dominion Bank losing 0.3 percent to C$57.73. Shares of energy producers slipped with the price of oil. Canadian Natural Resources Ltd shed 0.4 percent to C$46.25 and TransCanada Corp gave back 0.8 percent to C$56.01. Brent crude oil futures drifted further below $103 a barrel as a strong dollar and plentiful supplies continued to pressure prices. (Editing by Jeffrey Benkoe)