* TSX rises 137.09 points, or 0.96 percent, to 14,368.98 * All 10 main index sectors advance * CN Rail, CP Rail are most influential gainers By Alastair Sharp TORONTO, March 18 (Reuters) - Canada's main stock index gained almost 1 percent on Tuesday as investors focused on signs that the crisis in Ukraine will not escalate and as central banker comments at home on slow growth were interpreted as meaning interest rates will remain low. The gains were broad, with each of the 10 main sectors on the index moving higher, and were led by the biggest and most liquid stocks, including Canadian Natural Resources Ltd and Canadian National Railway Co. The boost came as President Vladimir Putin signed a treaty to make Crimea part of Russia but said he did not plan to seize any other regions of Ukraine. "Whether or not Crimea was just the first step in Russia moving further into Ukraine was the biggest worry," said Allan Small, a senior investment adviser at HollisWealth. But even an escalation of those geopolitical tensions shouldn't clip Canada's all-time-high stock market, according to Barry Schwartz, portfolio manager at Baskin Financial Services. "Is it important to me or you or the average investor who owns good quality North American stocks?" Schwartz said of the situation in Eastern Europe. "No, there is no impact. "What really matters is the accommodation of the central banks in North America to continue to keep interest rates very low," he said. That monetary stance got a boost when Bank of Canada Governor Stephen Poloz warned about the risk of a prolonged period of sluggish growth and how that could mean that interest rates will stay low for longer. The Toronto Stock Exchange's S&P/TSX composite index ended up 137.08 points, or 0.96 percent, at 14,368.97, marking the biggest one-day gain since early February. Financials, the index's most heavily weighted sector, added 0.5 percent. Manulife Financial Corp climbed 0.8 percent to C$20.99, and Bank of Nova Scotia rose 0.6 percent to C$64.83. Energy shares, another heavy hitter on the index, gained 1.4 percent, with telecoms and consumer companies notching similar gains. Industrial shares jumped 1.2 percent, helped by gains in the country's two biggest rail operators. Canadian National Railway Co advanced 1.2 percent to C$63.39, and Canadian Pacific Railway Ltd gained 1.5 percent to C$173.68. Valeant Pharmaceutical International Inc jumped 3.1 percent to C$160.63 and Potash Corp gained 2.2 percent to C$38.66. Shares of gold producers gave back 0.4 percent, reflecting a fall in the price of bullion. Barrick Gold Corp slipped 0.3 percent to C$22.55. "Gold is down because the fear factor from Russia dropped a notch," Small said. Investors are also awaiting the U.S. Federal Reserve's policy decision on Wednesday, at the close of the Fed's two-day meeting.