Hong Kong Exchanges and Clearing is considering rule changes to make it easier and cheaper for Growth Enterprise Market-listed firms to move to the main board. Richard Williams, head of the listings unit, said yesterday the exchange was considering removing the requirements that GEM firms issue and print full versions of listing prospectuses when switching. 'GEM companies have been listed in the Hong Kong stock market for some time. It is a question of whether it is necessary for these companies to issue full versions of prospectuses when they shift to another board,' he said. Shares in Li Ka-shing's Tom Group will move to the main board on August 4, while the company's internet arm, Tom Online, will remain on the GEM board. Tom is the largest of 10 GEM firms making the jump, resulting from rule changes in April that allow main-board applicants to be exempted from the HK$50 million profit requirement if they have minimum assets of $4 billion and annual revenue of $500 million. A source at HKEx said the wave of transfers did not mean the GEM board was unpopular. 'The GEM is like secondary school while the main board is like university. The GEM has a role to help newly set up companies raise funds to develop their business,' the source said. 'When these companies grow bigger, it is natural for them to jump to the main board. It is not an exodus but an upgrade.'