* C$ at C$0.9783 vs US$, or $1.0222 * Currency moving in tight range amid cautious mood * Limp global growth prospects weigh By Alastair Sharp TORONTO, Oct 10 (Reuters) - The Canadian dollar was little changed versus its U.S. counterpart on Wednesday as investors took a more cautious tone on mounting concerns about global growth. Global stock markets and commodity prices weakened after the International Monetary Fund, in a semi-annual report, said the euro zone debt crisis was an increasing threat to global financial stability and that confidence was "very fragile." "The news seems to be more bearish than anything else, so the tactical bias for many of the desks that we're talking to, including our own, is to play defense in a market like this," said Jack Spitz, managing director of foreign exchange at National Bank Financial. At 9:17 a.m. (1317 GMT), the Canadian dollar was trading at C$0.9783 versus the U.S. dollar, or $1.0222, slightly stronger than Tuesday's North American session close at C$0.9786 to the U.S. dollar, or $1.0219. The resource-linked currency, which typically does well when investors are upbeat about the prospects for global growth, has moved in a range of just C$0.9745 to C$0.9809 against the greenback so far this week. The IMF's semi-annual report on the world's financial health followed a downgrade earlier this week by the international lender of its forecast for global growth. In addition, Alcoa , which kicked off the third-quarter earning season after the bell on Tuesday, lowered its global aluminum consumption outlook, citing China as the main reason. Most commodities, including copper and aluminum, were lower, which weighed on the currency of Canada, a major oil and metal exporter. Gold was heading for its first four-day losing streak since August. Crude oil bucked the trend as tensions in the Middle East keep supply concerns in the foreground. National Bank's Spitz said a number of upcoming events were also keeping investors cautious. These include a European Union meeting that could launch a Spanish request for aid or movement on Greece's debt crisis, an IMF meeting in Tokyo this week, the U.S. presidential election, and the looming U.S. "fiscal cliff" - government spending cuts and tax rises that are due to take effect early in 2013 unless Republicans and Democrats can agree alternative measures.