The rating on General Motors Co. reflects, among other factors: Standard&Poor's Ratings Services' expectation that GM can sustain its return to profitability in North America, even if EBIT margins do not improve significantly compared with 2010; The contribution from GM's strong shares in the growth markets of China (No. 1 market share) and Brazil (No. 3), where we expect sales to remain vibrant although potentially volatile; Our view that GM will continue to generate positive free operating cash flow (before any large voluntary pension contributions) in its global automotive operations; Our assumption that GM will use a portion of its substantial cash balances to address its massive unfunded global pension liabilities (underfunded in the U.S. by $17.1 billion