Konsortium Perkapalan, a Malaysian transport company, says it is offering to buy the 36.9 per cent of Diperdana Corp it does not already own for M$566 million (about HK$1.75 billion) in cash. The purchase of a 63.1 per cent stake in rival Diperdana was agreed upon in July. Konsortium - which is controlled by a son of the Malaysian Prime Minister - said that it later planned to sell at least 25 per cent of Diperdana to the public. Under an agreement with Diperdana in July, Konsortium agreed to buy a controlling interest in the company in return for the sale of some shipping assets to Diperdana. Under Malaysian company law, Konsortium is required to make a full offer for Diperdana because it will control more than 33 per cent of the company once July's transaction is approved by shareholders.