The board of Kuwaiti telecom operator Zain has approved opening the company’s books for due diligence by UAE’s Etisalat, which has offered to buy a stake in the firm, Reuters has reported, citing a source close to the deal. Etisalat, the Gulf’s second largest telecoms group, offered in September to buy a 46 per cent stake in Zain for KD1.7 a share, in a deal worth just under $12bn. Last Wednesday, Etisalat said it was making any deal dependent on the sale of Zain’s Saudi assets.