Britain's biggest pharmaceutical company, GlakoSmithKline, has said it will stop paying doctors tens of millions of pounds a year to promote its drugs.

GSK has committed to ending payments to doctors for recommending its drugs to other doctors at medical conferences. It will also stop linking the bonuses of sales staff to the number of drugs they sell.

Sir Andrew Witty, GSK's chief executive, said pharmaceutical firms must end the decades-long standard practice of paying independent doctors to promote drugs, and make sure "patients' interests always come first".

"We recognise that we have an important role to play in providing doctors with information about our medicines, but this must be done clearly, transparently and without any perception of conflict of interest," he said.

GSK refused to state how much money it pays doctors to promote its drugs, but a company source said it was in the region of "tens of millions of pounds a year".

In the UK, where drug firms are forced to declare such payments, GSK paid doctors £1.9m in speaking and advisory fees last year.

GSK said the payments, which can amount to tens of thousands of pounds for a single lecture, will end by 2016. The company will also stop paying for doctors' flights, hotel bills and other expenses to attend conferences. Last year GSK paid out £900,000 in such expenses.

The Association of the British Pharmaceutical Industry estimates that British drug firms pay £40m a year in expenses to UK doctors.

Instead of paying independent doctors for conference presentations, GSK will hire more in-house doctors. Doctors involved in clinical research will still be paid.

GSK's commitment to stop paying doctors comes five months after it was accused of behaving like a criminal godfather in China, bribing doctors with cash and prostitutes in return for prescribing its drugs. Last year it paid a record $3bn (£1.9bn) in fines to settle claims that it tricked and bribed US doctors into prescribing children dangerous antidepressants.

The company said the changes were not linked to either scandal.

Ben Goldacre, a doctor and Guardian columnist, who helped expose drug companies' manipulation of clinical trial data, said he expected GSK's move would shame the rest of the industry into ending payments to doctors. However, he said the public would be "shocked and amazed" that drug firms were ever allowed to pay doctors.

"The pharmaceutical industry's reputation is terrible, and when the public find out about this sort of thing they lose trust not just in the pharma industry but medicine in general.

"Influential doctors are paid thousands or tens of thousands of pounds to teach colleagues about which drugs are best," he said. "I suspect that there are doctors whose lectures aren't entirely independent."

Goldacre said every doctor who accepted free training from a pharmaceutical company should declare it in notices in waiting rooms detailing the companies and their drugs.

"They [pharmaceutical companies] don't need to engage in shady practices to turn a profit," he said.

GSK, the world's third biggest drug company, made pre-tax profits of £6.7bn last year.

The company has already agreed to publish clinical trial data in a move that campaigners hope will increase the likelihood of medical breakthroughs and protect patients from ill-advised prescriptions.