A UK court has backed a bid to split SABMiller's shareholders into two groups ahead of a vote on its £79 billion takeover by Budweiser brewer Anheuser-Busch InBev (ABInbev).

Two of SABMiller's largest shareholders, Altria Group and Bevco, will be split off into a separate group from the rest of the brewing giant's shareholders when the deal goes to a vote on September 28.

Together, Altria Group and Bevco own about 40 per cent of SABMiller.

The shareholder vote requires 75 per cent approval from shareholders. The High Court ruling means each group will have to reach that threshold to approve the deal.

The SABMiller board has recommended that shareholders accept the Belgian brewer's all-cash offer of £45 a share, up from its earlier price of £44, valuing the London-listed firm at around £79bn.

Investors including hedge fund Elliot Engagement and Aberdeen Asset Management have raised concerns about the deal. Aberdeen said it welcomed the court's ruling.

"We are pleased the court has acknowledged the reality of the situation which will help to ensure that the views of the rest of the investor base have due weight," it said.

The asset manager reiterated plans to vote against the deal, adding it was uncomfortable with its structure and believed the takeover offer undervalued SABMiller.

The firm urged other shareholders to follow suit.

"We would welcome other investors who value good corporate governance and recognise the superior long-term value from continuing to hold SABMiller as a standalone entity voting in a similar fashion."

Nik Stanojevic, an equity analyst at wealth manager Brewin Dolphin, explained that the shareholder split slightly increases the probability of a failed deal.

That may be good news for stakeholders like Aberdeen, but Mr Stanojevic stressed that there was only a three to five per cent chance that the takeover would be struck down.

"The probability that it falls through, I think, is probably quite low," he said.