* C4 at C$0.9968 to the US$, or $1.0032 * Currency tracks equities, commodities lower * U.S. GDP data eyed for C$'s next move By Alastair Sharp TORONTO, Oct 26 (Reuters) - The Canadian dollar weakened on Friday versus its U.S. counterpart, as commodity prices and equity markets retreated ahead of a key reading of economic growth in the United States, Canada's largest trading partner. At 8:15 a.m. (1200 GMT) the Canadian dollar was at C$0.9968 to the greenback, or $1.0032, compared with C$0.9939, or $1.0061, at Thursday's North American close. The currency weakened into that close after disappointing financial results from technology giant Apple Inc and data showing Spanish unemployment hit a record 25 percent in the third quarter. European stocks were on track for their worst week in a month, and gold, oil and copper all eased. Traders said a poor showing from the 8:30 a.m. U.S. gross domestic product data could weaken the Canadian dollar even further, perhaps pushing it below parity with the U.S. dollar for the first time since August. "Ultimately, there's a fair bit of congestion in terms of technical levels to get through, but it could create some momentum to see some of the long Canadas in the speculative market covered in the event that we do see it through parity," said Jack Spitz, managing director of foreign exchange at National Bank Financial. The two-year bond was up 3 Canadian cents to yield 1.132 percent, while the benchmark 10-year bond rose 34 Canadian cents to yield 1.862 percent.