Anheuser-Busch InBev (AB InBev) has upped its bid to acquire SABMiller ahead of a Wednesday 14 October deadline.

AB InBev has raised the all-cash part of its bid, which is meant for majority of SABMiller’s shareholders from £42.15 to £43.50 per share, a premium of 48 percent to SABMiller’s closing price on September 14, the day before the initial bid.

AB InBev is also offering a cash-and-unlisted share deal for SABMiller’s two largest shareholders, tobacco company, Altria Group, who control 27 percent of SABMiller’s shares and the Santo Domingo family, who hold 14 percent of the company’s stocks.

AB InBev raised the cash-and-unlisted part of the offer from £37.49 to £38.88 a share in an effort to win over the support of the Colombians, which is crucial for the deal to go through.

Altria, who has three directors on SABMiller’s board had already last week agreed to a lower offer of £65bn, but the two Santo Domingo directors on the board voted along with the majority of SABMiller’s board to reject the bid.

Monday’s sweetened offer would be AB InBev’s fourth, following rejections of cash offers at £38, £40 and £42.15 per share.

Bloomberg reported late on Monday evening that SABMiller’s board had decided the offer was not high enough to start detailed discussions with AB InBev. According to people close to the ongoing discussions, SABMiller wants a price somewhere closer to £45 a share for them to agree to further discussions.

AB InBev has until 5pm on Wednesday 14 October to conclude the deal, or they would have to wait another six months before making another bid.

The merger, if it goes through, would create the world’s largest beer company, with controlling interest of 30 percent of the world’s beer volumes and will have about $244bn in annual sales.