YIU Wing International Holdings, the property development and construction group, has postponed a US$20.2 million deal to acquire a 40 per cent stake in a Chinese-run hydroelectric plant in the Philippines. Chairman Cheung Yiu Wing said it would need until the end of June to finalise due-diligence requirements and approval from the Philippine officials. Last November the company announced it had paid a $5 million cash deposit, with the balance to be a mixture of shares and cash, for a stake in China Chang Jiang Energy Corporation. It estimated a return of more than 20 per cent from the plant. The deal was made through wholly-owned subsidiary, Walton Enterprises, whose sole asset when purchased in January 1994 was a 20 per cent interest in Changfa Electric Equipment, a Sino-foreign joint venture operation which builds power stations. The Philippine Government has guaranteed Yiu Wing that electricity produced at the plant, which has an annual production volume of 480 million kilowatt-hours, will be used for domestic consumption. Under the deal the plant's production is capped but there is a floor to the minimum level.