 Alcoa Corp. AA, -2.57 late Wednesday reported a second consecutive quarterly loss, saying it has tried to lessen the impact throughout the year of challenging market conditions that included high costs for raw materials and energy and lower prices for its alumina and aluminum. The company, which did not provide a broad market outlook for the two products, said it had lost 374 million, or 2.12 a share, in the fourth quarter, compared with a loss of 392 million, or 2.11 a share, in the year-ago period. 