* TSX up 15.48 points, or 0.13 percent, at 12,368.46 * Financial, healthcare, energy sectors fall; materials rise * Catamaran shares drop nearly 4 percent By John Tilak TORONTO, Nov 6 (Reuters) - Canada's main stock index was little changed at midday on Tuesday with weaker financial and healthcare stocks offsetting rising material shares as investors guardedly awaited the outcome of the U.S. presidential election. Capping a long and bitter campaign, Americans began casting their votes to decide whether to give Democratic President Barack Obama a second term or replace him with Republican challenger Mitt Romney. Whoever is elected will have to deal with the fiscal cliff that faces the U.S. government, said John Ing, president of Maison Placements Canada. "I think either gentleman faces very difficult problems and needs to show leadership. Right now the Street is pretty cautious." "This is going to be a nothing day," Ing added. "The consensus is whether it is Romney or Obama, both would be negative for the market," The Toronto Stock Exchange's S&P/TSX composite index was up 15.48 points, or 0.13 percent, at 12,368.46. The index's financial subgroup was lower, with Royal Bank of Canada, the country's largest bank, down 0.42 percent at C$57.11. The energy subgroup, one of the largest in the index, was also down, slipping 0.02 percent. Pharmacy benefit manager Catamaran Corp was down 3.98 percent at C$47.55. Shares of Catamaran's U.S. competitor, Express Scripts Holding Co, tumbled about 15 percent after its CEO said Wall Street's outlook for its 2013 results in may be too aggressive. The index's materials sector, which includes mining stocks, rose 0.27 percent. Diversified miner Teck Resources was up 1.58 percent at C$33.40. Goldcorp Inc rose 0.67 percent to C$43.55 and fellow gold miner Yamana Gold Inc was up 1.57 percent C$19.36.