Guoco Group will spend HK$5.35 billion on its controversial share buy-back after exercising an over-allocation option to increase the number of shares purchased to 107 million. The shares are being bought at HK$50 each - the minimum in the HK$50 to HK$55 range offered to investors - after enough tendered share offers were received at the lowest price. Shares tendered above HK$50 were rejected. The stake of the Quek family will rise from 34.68 to 46.28 per cent after the buy-back. Guoco received valid tenders of 147.73 million shares, or 34.27 per cent of the company. The HK$50 sale price is a 6.16 per cent premium to the closing price on September 7, the last trading day before the buy-back was announced. Guoco shares closed at HK$50.25 yesterday.