Google chief executive Eric Schmidt has resigned from Apple's board of directors, in a move which many see as an indication of Google's increasing intention to occupy and dominate the operating system markets.

Schmidt had been a member of Apple's board for three years, but resigned because of the increasing overlap between the Google and Apple businesses.

"Unfortunately, as Google enters more of Apple's core businesses with Android and now Chrome OS, Eric's effectiveness as an Apple board member will be significantly diminished, since he will have to recuse himself from even larger portions of our meetings due to potential conflicts of interest," said Apple chief executive Steve Jobs.

"Therefore, we have mutually decided that now is the right time for Eric to resign his position on Apple's board."

Schmidt's position as a non-executive director of Apple had come under increasing scrutiny over the past year, as Google entered the mobile phone operating system market with Android, and then announced its Chrome OS to rival Apple's Mac OS X.

The two companies also compete in the browser stakes. Apple's Safari and Google's Chrome occupy third and fourth place in terms of market share, behind Internet Explorer and Firefox.