Tata Teleservices chief executive officer Darryl Green has quit the company after a two-year stint.

"Green has resigned... he has not been sacked," a company source said, adding that he had been talking to the management about his exit for quite some time.

The parting was amicable, the source said when asked whether the move was a fallout of differences he might have had with the Tatas.

Green had joined Tata Teleservices, which offers CDMA mobile and landline telephone services, in June 2005. He was heading Vodafone's Japan operations prior to that.

He was the only expatriate CEO in the Indian telecom industry and held the post even before government allowed foreign executives to head Indian telecom companies in March this year.

The company is expected to issue a statement later in the day.