* TSX falls 31.97 points, or 0.26 percent, to 12,467.58 * Six of 10 main sectors decline * Barrick Gold shares fall 1 percent By John Tilak TORONTO, Jan 8 (Reuters) - Canada's main stock index fell on Tuesday on investor caution over the U.S. fourth-quarter earnings season and a decline in Barrick Gold Corp after it pulled out of talks to sell its African unit. Barrick shares fell 1 percent after the world's top gold miner said it had ended talks to sell a stake in its struggling African Barrick Gold subsidiary to a Chinese buyer. The stock played a major role in leading the market lower. Investors were also approaching the earnings seasons in Canada and in the United States, where results got under way on Tuesday, with a mixture of hope and caution, said Irwin Michael, portfolio manager at ABC Funds. "People are hoping that 2013 will be a better year than it was in 2012, particularly in Canada. But there's still a lot of confusion, a lot of cash on the sidelines," he said. "It's still early in the year. People are waiting to get better visibility," Michael added. The Toronto Stock Exchange's S&P/TSX composite index was down 31.97 points, or 0.26 percent, at 12,467.58. Six of the 10 main sectors on the index were down. The materials sector, which includes mining stocks, was little changed as Barrick's move was offset by gains in fertilizer giant Potash Corp, up 0.5 percent at C$41.33, and miner Goldcorp Inc, which rose 0.8 percent to C$34.96. The energy sector shed 0.6 percent. Canadian Natural Resources fell 1.5 percent to C$29.34, and Suncor Energy Inc was down 0.6 percent at C$33.04.