TSX sheds 82 points
Fitch lowers Portugal debt rating
Miners lifted by merger activity
N.Y. weak ahead of housing data
Health sector supports N.Y.
Commodity prices wilt under the weight of a stronger greenback
Commodities depressed as U.S. dollar climbs
Dow climbs 45 points
Citigroup cuts rating on the global financial sector
Loonie edges closer to parity with U.S. greenback