(Adds details on specific stocks, updates prices)
* TSX down 21.05 points, or 0.14 percent, to 15,389.68
* Eight of TSX's 10 main groups move lower
* Index on track for 0.4 pct slip over week
TORONTO, May 26 (Reuters) - Canada's main stock index moved slightly lower in morning trade on Friday as gains for gold miners on a push higher in bullion were offset by declines in some heavyweight banks.
At 10:57 a.m. ET (1457 GMT), the Toronto Stock Exchange's S&P/TSX composite index .GSPTSE was down 21.05 points, or 0.14 percent, to 15,389.68.
Eight of its 10 main groups were lower, although decliners only slightly outnumbered advancers overall.
The index is on track for a 0.4 percent slip in the holiday-shortened week.
Gold miners were among the strongest gainers, as political uncertainty led investors to shun riskier assets in favor of the precious metal, pushing it to its highest in nearly four weeks. O/R
Agnico Eagle Mining AEM.TO gained 2.2 percent to C$66.45 and Goldcorp G.TO was up 0.9 percent at C$18.42.
But Barrick Gold ABX.TO fell 0.5 percent to C$21.86 after it said on Thursday that two mines at its majority-held Acacia Mining ACAA.L , which account for some 6 percent of Barrick's 2017 production guidance, are impacted by Tanzania's current concentrate export ban. materials group, which includes precious and base metals miners and fertilizer companies, added 0.5 percent.
Several of the country's biggest banks pulled back after gains following their earnings reports earlier in the week, with Royal Bank of Canada RY.TO down 0.3 percent to C$93.42 and Toronto-Dominion Bank TD.TO off 0.4 percent at C$63.76.
BlackBerry Ltd BB.TO rose 1.9 percent to C$15.40 after announcing the final amount it will receive from Qualcomm (NASDAQ:QCOM) in a royalty dispute.