DIAGEO Plc, the world's largest spirits maker, has offered to buy additional shares in Kenya's East African Breweries to boost its stake by a third to 65%, it said. Diageo is offering to buy 118.39 million shares at 192 shillings ($1.59) each, the multinational drinks group said in a statement, amounting to a 40% premium over the market price. The offer closes on March 10, next year, Diageo said, adding that it will not seek to take over the entire company should it attain its desired level of ownership, and it will keep the company listed. Diageo has been seeking to…