GERALD Mosse has accepted the Royal Hong Kong Jockey Club's offer to extend his visiting rider's licence by another month. The brilliant French jockey, successful 10 times from just five meetings, can now ride in the Derby on February 27, before leaving in early March to resume his position at home as first jockey to the Aga Khan. Mosse said last night: ''I rang France today and spoke to the Aga's people. ''They said it was no problem to stay on for the extra month which makes me very happy indeed. ''I have always loved riding in Hong Kong and just hope my recent good luck can continue.'' Mosse rode a double at Happy Valley on Wednesday night to add to a double at Sha Tin on Sunday and a four-timer at the previous Valley meeting. But he has a three-meeting careless riding suspension hanging over him against which he has appealed. The appeal is expected to be heard next week. Meanwhile, India's leading studmasters, the Poonawalla brothers, will make a lightning trip to Sha Tin tomorrow in the hope of seeing crack stayer Astonish leapfrog into the top bracket here. Dr Cyrus and Zavaray Poonawalla will arrive from Bombay tonight but will make a dash back to Kai Tak immediately after the running of the featured Centenary Vase tomorrow so that they can be back home for the Indian Oaks on Sunday where they are represented by three runners. The Poonawallas bred Indian Triple Crown winner, Astonish, who stunned most punters with a superb win over 2,000-metres at his first local start. He is raced locally by Rusy and Purviz Shroff but is eventually destined to return to India for stud duty with the Poonawallas. Astonish steps up in distance but that will be very much in his favour as will the fact that he gets 20 pounds from topweight Fortune Leader. Half of the eight-runner field will be racing out of the handicap. Owner Rusy Shroff said: ''The telephones and fax machines have been running for a couple of days. As the Centenary Vase is Race Six we are hoping that they will have just enough time to get to the airport and get a 5.20 pm flight back to Bombay. ''The win of Astonish on his debut was very big news in India and they were absolutely delighted. He has a very good chance in this race and they would love to see him win again.'' Zavaray Poonawalla said from Bombay yesterday: ''We have decided to make the trip because we believe - and hope - that Astonish can win again. This is a much better trip for him than 10 furlongs and he will not be carrying much weight. ''His debut win was a fairytale come true and was a great result for Indian racing and breeding.''