In a major departure from industry practice, GlaxoSmithKline, the sixth-largest global drug maker, announced Tuesday that it will no longer hire doctors to promote its drugs. The company also will stop tying compensation for sales representatives to the number of prescriptions written for drugs they market. The changes will be made worldwide over the next two years. The New York Times broke the news late Monday. But the company said it will continue to pay doctors for research, consulting and "market research." It will also continue to provide unsolicited funding for continuing medical education activities run by "independent" groups.