Under the deal, Sina Mobile will distribute a new game from Green Tomato called Fish Bo Bo, a fish nursery game similar in concept to the Tamagotchi.

The game has accumulated more than 100,000 subscribers since it was released in Hong Kong less than two months ago, according to Green Tomato's founder and chief executive, Arthur Chang.

He said the company now had a million users in China, through its partnerships with Sina, China Mobile and China Unicom.

Sina Mobile vice-general manager Peter Cai said Green Tomato's fish game was 'well received by young mobile users in China, recording a substantial growth in subscriber base within a short period. We expect that the number of subscribers will continue to grow'.

Fish Bo Bo, which works across different platforms and handsets, allows players to breed their favourite virtual fish.

Mainland content developers are finding that working with mobile or internet service providers in revenue-sharing agreements is a financially viable method of developing games and other products. Phone users are encouraged to use value-added services, such as SMS, and content providers receive a slice of the additional fees charged for using their products.

Mr Chang said Green Tomato was able to break even last year despite being less than a year old.

Mr Chang was previously the managing director for the domain name services provider Verisign Hong Kong. He set up Green Tomato last February. The company has 20 employees in Hong Kong and four in Shanghai.

The global mobile games market will be worth ?1.65 billion (about HK$15.9 billion) in 2006, compared with ?460 million last year, according to a report by the Wireless World Forum (W2F) published in November.

W2F research director Graham Brown said growth in Europe and the United States over the next three years would be significant. Although the US was a late starter, the number of mobile gamers there would catch up with the rest of the world over the next five years.

'Japan's dominance will be eclipsed by China and the US in 2006,' he said.

Green Tomato's key product is middleware that allows third-party developers and content providers to connect to mobile operators. This middleware is called Wireless Distributed data exchange Engines, or Wi-DeXE.

Wi-DeXE received $2 million in funding support from the government's Small Enterprise Research Assistant Programme.

Mr Chang said the government's support for technology start-ups had matured in recent years. The Hong Kong Science and Technology Parks' incubation programme, which helps technology start-ups, offered more than just rental subsidy.

'In 1994, I set up Asian Information Resources, which is now listed on the Growth Enterprise Market. I looked at joining the government's incubation programme for technology start-ups then but found it unattractive and quite primitive,' he said.

'I looked at the programme again after I set up Green Tomato, and found it had improved a lot. There is more networking support. You gain more visibility and get put in touch with other companies in the same business so you get a good introduction,' he said.