THE world's top six national teams will clash at the Hongkong Coliseum next month for the biggest purse - US$225,000 - ever offered in women's volleyball. Eight countries have been invited to compete in the US$1 million Grand Prix series and each team will have to play in three, four-team round-robin tournaments, the first next week in Japan. Playing in the Japan tournament, from May 28-30, are Russia, Cuba, Germany and the host team while the next leg in South Korea from May 29-31 will feature China, Brazil, the US and the home side. Other preliminary tournaments are from June 4-6 in Thailand and Malaysia and on June 11 and 13 in Australia and Taiwan. Drawn for the Thailand tournament are Russia, Cuba, South Korea and Brazil while China, Japan, Germany and the US will play in Malaysia. In Australian it will be China, Russia, Cuba and the US and in Taiwan, Germany, Brazil, Japan and South Korea. The top six teams qualify for the finals, named the Hutchison Telephone Challenge, in Hongkong. Shek Chun-tat, president of the Hongkong and Kowloon Volleyball Association, said: ''The series features the best women's teams and they are coming here for the biggest purse ever offered in this sport.''