Anson Chan 'quits' - finance chief tipped as her successor
Top civil servant Anson Chan Fang On-sang is understood to have resigned less than 1.5 years before her term was due to end.
Financial Secretary Donald Tsang Yam-kuen is tipped to succeed her.
Television news bulletins quoted government sources last night as saying she had tendered her resignation after nearly 40 years as a civil servant. She was quoted as saying that it was now time for her to do other things.
A formal announcement confirming that she had stepped down would be made soon, the sources said, adding that she would stay on for a few months to smooth a transition.
Mr Tsang left the Central Government Offices shortly before 7pm, without commenting on the reports. Any appointment of principal officials has to be made by the central Government.
Mrs Chan's resignation would trigger the most far-reaching reshuffle at the top level of government since the handover. There has been constant speculation that she has been at odds with Chief Executive Tung Chee-hwa.