When Hong Kong stock exchange deputy chief executive Herbert Hui predicted earlier this month that more companies from the territory would be listing on the Singapore exchange, he must have had some insider information. For within weeks two more companies have picked the republic for their primary listing. Last week saw the publication of the prospectus for fish supplier Pacific Andes, and even as that was being absorbed by local investors, mouldings group Lung Kee announced its intention of joining the drift south, which some local commentators fondly, but erroneously, believe is part of the 1997 effect. Lung Kee, and those that will inevitably bear out Mr Hui's words later, can be assured of a warm welcome when they arrive on the island. Pacific Andes, hardly a household name in Singapore, attracted 250 analysts when directors introduced the company last week. There must have been a glow of mutual self-satisfaction among the group. They better enjoy it while they can, for that initial reception can be as perishable as the group's products. For while the promises of higher price-earnings ratios and full subscriptions which Singapore holds out to potential listing companies are apparently fulfilled, the interest quickly dies away in the after-market. Directors of Singapore listed companies from Hong Kong chorus the single complaint: 'Not enough liquidity.' For the company, this is not a disaster. After all, they got their cash, but these days good companies like to see shareholders are well treated and can easily buy, and sell, stock. So it is frustrating for the Hong Kong companies which have chosen Singapore on the grounds that it appreciates industrial companies better than the home market, to find that investors are sometimes locked in, or locked out. Even Victor Lo Chung-wing, who has successfully listed two spin-offs of his Hong Kong listed Gold Peak Industries in Singapore, frets at the lack of liquidity, although he otherwise has no complaints. His automotive electronics group GPE Industries listed in November last year at 45 US cents a share and a price earnings (PE) ratio of 10.2 times, which he said at the time was better than would have been commanded in Hong Kong. This week GPE shares were 54 US cents, having touched 60 cents, and are now on a historical PE of 12.3 times. The Gold Peak parent is valued in Hong Kong at less than nine times earnings. Sometimes even the PE argument does not hold up. Directors of toymaker Wah Shing, part of the South China Holdings group, were privately disappointed that the float at the beginning of the year was on 7.63 earnings, lower than they had expected. Even more so now. Wah Shing is currently at just 5.3 times, pretty much in line with its Hong Kong parent. Wah Shing and GPE are quality companies, respected in their field. Mr Lo and his directors take a great deal of trouble to inform Singapore investors of GPE's developments and prospects through personal visits, press conferences, analysts meetings and exhibitions. If he can't generate some action in the shares, it's hard to see who can. Certainly it's not the job of the Stock Exchange of Singapore to pump up liquidity. It offers its market, approves the listings, and then it's up to the invisible hands. Obviously the merchant bankers and brokers who bring the companies to market should do their best to maintain interest in their stocks, but their influence is largely limited to fund managers. It is the retail investors' valuable liquidity which appears to be missing in Singapore. Some responsibility must be put on the insistence of the authorities that the overseas listings are quoted in foreign currencies, usually US dollars. This is part of the policy that the Singapore dollar will not be internationalised. Currency procedures have been streamlined, but so far that has not provided much comfort for Hong Kong directors who face the choice of undervaluing their company in Hong Kong or see trading in their stocks quickly dry up in Singapore.