Anheuser-Busch InBev has raised its takeover offer for SABMiller, as the world's largest brewer tries to win over its smaller rival to the idea of creating a giant that would make nearly a third of the world's beer. 

The maker of Budweiser and Stella Artois is offering £43.50 per share in cash to most SABMiller shareholders.

There is also an option available for some to take a lower-priced mix of cash and shares. 

AB InBev has until tomorrow evening to launch a formalbid for SABMiller, in what would be the biggest UK company takeover ever. 

Today's sweetened offer is the company's fourth, following rejections of cash offers at £38, £40 and £42.15 per share. 

Three of SAB's top 10 shareholders had spoken out in support of the board rejecting the previous offer, which SABMiller said "very substantially" undervalued the company. SAB declined to comment on the new offer. 

The cash-and-share alternative is meant to be unattractive for institutional shareholders

 It was designed "for and with" SABMiller's two big shareholders, Altria Group and the Santo Domingo family of Colombia, which together own about 41% of the stock. 

The proposal is conditional on Altria and the family electing the share alternative for all their shares. 

Altria had already endorsed AB InBev's last offer, while the Santo Domingos rejected it. 

Taking into account the discounted price of the share alternative, the new offer would see AB InBev pay £67 billion for the maker of Peroni, Grolsch and Pilsner Urquell. The previous offer would have seen the company pay £65 billion. 

South Africa's Public Investment Corporation (PIC), Poland's Kulczyk Holding and Scotland's Aberdeen Asset Investments - respectively SABMiller's fourth, fifth and seventh-largest shareholders - had all publicly sided with SABMiller. 

Altogether their holdings account for 8.2% ofthe company. 

It remains to be seen whether the new bid will be embraced by the Santo Domingos, which own 14% of the company following the sale of their Grupo Bavaria business to SABMiller in 2005.