The BBC's biggest stars are paid large salaries to fend off bids from rival broadcasters, the BBC's director general Mark Thompson has said.
BBC Radio 2's Terry Wogan is the UK's most listened-to radio DJ
Commercial companies were offering BBC stars "far, far higher rates than they are currently getting", he said.
Press reports last month suggested BBC Radio 2 presenter Terry Wogan was earning £800,000 a year.
Mr Thompson said BBC salaries were growing by 2% a year compared with 2.7% for the media as a whole.
"However, we absolutely do believe that in some categories of key talents, the rates are running very differently," he said at a seminar hosted by the Department for Culture, Media and Sport.
"What we try to do is offer artists, producers and programme makers an amazingly wide range of creative work," he added.
Mark Thompson said the talent market was highly competitive
The BBC is investigating how the salary figures reported in the press were leaked.
The corporation said it was "concerned" at how such information made its way into the public domain.
The Sun reported that BBC Radio 1 breakfast host Chris Moyles earned £630,000, while the Daily Mirror published a figure of £540,000 for new Radio 2 drivetime presenter Chris Evans.
Celebrity salaries have traditionally been closely-guarded secrets, with the corporation refusing to comment on individual contractual details.