* As on Wall Street, soft Q4 earnings seen for Canada * TSX company profits are forecast to rise only 0.3 pct y/y * TSX earnings for 2012 seen slipping 1.4 percent * Biggest weakness expected in energy, mining stocks * Banks also seen losing steam By Claire Sibonney TORONTO, Jan 20 (Reuters) - Financial results from Canada's biggest companies are likely to disappoint investors in the coming weeks with weak global growth and mixed commodity prices expected to have pummele