Following a weak start on Saturday, the Saudi Arabian Tasi stock market index gained 0.37% Sunday, to close at 6,420.70. Saudia Dairy & Foodstuff Co. posted the largest advance (up 6.58% at SR40.50 followed by National Petrochemical Company (gaining 4.23% at SR18.50). Zain KSA, the Saudi unit of Kuwait's Zain telecom operator, was the second most liquid share, gaining 1.24% at SR8.15. According to Sico bank, Qatar Telecom is interested in buying Zain KSA, a move which could clear a regulatory hurdle for UAE's Etisalat. On September 28, Etisalat expressed interest in acquiring 46% in the monther company Zain.