Lee Kai-Fu became the face of Google China

The man who led Google's expansion into China is leaving the company to start his own business.

Lee Kai-Fu, who joined from Microsoft in 2004, will step down as president of Google in greater China in September, the company said.

When he joined, Microsoft sued Google and Mr Lee, claiming he had violated an agreement that prohibited him from working for a rival for one year.

The two sides later settled out of court, without releasing details.

Mr Lee went on to become the face of Google China.

But during his reign Google China had a difficult relationship with Beijing censors.

In June, access to Google in some parts of China was disrupted, amid a row over what Chinese citizens should be allowed to view over the internet.

A Chinese official also accused Google of spreading pornography and breaking Chinese law.

"Kai-Fu has made an enormous contribution to Google over the last four years, helping dramatically to improve the quality and range of services that we offer in China," said Alan Eustace, Google's senior vice president for engineering.

Mr Lee will be replaced by John Liu, who currently leads its greater China sales team.