ONE of the territory's most eligible bachelors has decided to forgo lavish celebrations for his wedding next Sunday and donate the considerable costs amounting to $3 million to the Catholic Diocese of Hongkong instead. Mr Victor Li, the eldest son of property-to-communications tycoon Li Ka-shing - reputed to be the richest Chinese in the world - is to marry Miss Cynthia Wong, 24, at the Catholic Cathedral in Caine Road. The bride is the daughter of retired businessman Mr Philip Wong and his wife Lily, who have flown in from their Vancouver home for the wedding. Twenty-nine-year-old Victor, deputy managing director of Cheung Kong (Holdings) Ltd, met Cynthia while she was studying in Canada and he was managing the family business interests over there. Their romance continued after they both returned to Hongkong: he to join the family holding company and she to work for Citibank. Miss Wong has since given up her job, as a spokesman for the Li family commented, ''to prepare for marriage''. The couple presented their generous monetary gift to Cardinal John Baptist Wu and expressed the hope that other couples planning their nuptials might consider a similar gesture to help some worthy cause. The money will be shared between the Diocesan Pastoral Centre For Disabled ($1.5 million), St Joseph's Home For The Aged ($700,000), St Mary's Home For The Aged ($700,000) and Maryknoll Convent School Educational Trust ($100,000). Still single is Victor's 26-year-old brother, Richard, who is executive director of Hutchison Whampoa.