US ratings agency Moody's Investors Service on Monday downgraded its outlook for GlaxoSmithKline from stable to negative.
However, the agency said it had kept its long-term A1 rating for the British pharmaceutical company and its subsidiaries unchanged.
Moody's said in a statement that GSK's outlook was hurt in part by the debt-financed acquisition of Human Genome Sciences Inc, a US- based biopharmaceutical corporation; legal settlements related to past investigations in the United States and product liability cases as well as large share buybacks.
Moody's said the ongoing investigation of alleged bribery by GSK employees in China was not the trigger for the change in outlook.
GSK, however, has said that it is relaxed about the decision, as it won't affect access to capital markets.