* TSX up 15 points, 0.1 pct, at 12,168.74 * Eight of 10 sectors stronger By Claire Sibonney TORONTO, April 20 (Reuters) - Toronto's main stock index edged up Friday, as an improvement in German business sentiment countered nervousness about the euro zone debt crisis, and solid North American corporate results propelled what has been a mostly positive earnings season. Eight of the 10 sectors were firmer, though weakness among miners dragged on broader gains. Key names on the upside included Cameco Corp, up 3 percent to C$21.68, Toronto-Dominion Bank, up 0.2 percent to C$84.12 and Potash Corp, up 0.6 percent to C$43.40. "Some people are starting to look at some of these commodity stocks, they feel they've been oversold the last few weeks and they're starting to pick some entry levels in them," said Bruce Latimer, trader at Dundee Securities. At 10:23 a.m. (1423 GMT), the Toronto Stock Exchange's S&P/TSX composite index was up 15.05 points, or 0.12 percent, at 12,168.74. The index briefly turned negative in early trade and Latimer cautioned that an options expiry on Friday may contribute to more volatility in the session. On the data front, the influential German Ifo survey unexpectedly rose for the sixth month in a row in April in a sign that Europe's largest economy continues to outpace peers and shrug off persistent worries about the euro zone debt crisis. In individual company news Canadian Pacific Railway, Canada's second-biggest railway, which is fighting a proxy battle with its biggest shareholder, rose 0.2 percent to C$76.16 after reporting first-quarter profits more than quadrupled. In the United States, better-than-expected results from Microsoft and General Electric propelled what has been a solid earnings season to date. On the downside, Barrick Gold fell 0.9 percent to C$40.37, Sun Life Financial lost 0.8 percent to C$24.61 and Canadian National Railway slipped 0.3 percent to C$79.36.