Aberdeen Asset Management, a top-10 shareholder in the UK’s beer giant SABMiller, has said a revised £79billion bid from rival AB Inbev is still “unacceptable”.

But analysts have speculated that £45 was the target for many big investors when the biggest ever bid for a UK company was first unveiled at £42.15 a share last October, and subsequently increased to £44.

Belgian-owned ABInbev, home of Budweiser, Stella Artois and Corona, is already the world's biggest brewer while the UK’s SABMiller is the number two with brands including Peroni and Grolsch. A merged group would be worth around $275bn (£206bn) and combine AB InBev's dominance of Latin America with SABMiller's strong presence in Africa.

The revised bid is a response to the slide in sterling following the Brexit vote which made the offer less attractive for overseas investors, threatening to derail the deal. For a foreign dollar-based investor, the cash offer had dropped by 12 percent since June 23.

SABMiller said its chairman talked with his counterpart at AB InBev on Friday about the offer in the light of exchange rate volatility and market movements, although they did not discuss the new terms.

AB-Inbev also tweaked the terms of an alternative share-and-cash structure designed for SABMiller's two largest shareholders, raising the cash element by 88p a share.

Aberdeen Asset Management, with a 1.17 percent stake in SAB Miller and only 0.06per cent in its suitor, said the revised offer was still unacceptable, as it still favoured those shareholders US tobacco company Altria and Columbian-owned BevCo.

"We have engaged with SABMiller's Board on the differential treatment of shareholders since the deal was first constructed. The way that the value of the partial share offer has diverged from the cash offer has compounded our discomfort," Aberdeen said.

Altria and Bevco should not be able to vote on the cash offer as they were inherently conflicted by their future stakes in AB InBev if the deal completes, the Scottish investor added.

"We believe the board's only choice is to treat Altria and Bevco as a separate class of shareholders and would urge them to make a public statement to this effect."

Failing a new offer, Aberdeen would "happily" remain a long-term shareholder in SABMiller, it added.

The offer values SABMiller at around £79 billion and analysts suggested the deal was now likely to go through.

SABMiller, which provisionally agreed the deal struck in October, said it had taken on Centerview Partners as a new financial advisor and would consult with Centerview and with shareholders before formally considering the revised offer.

The takeover is still awaiting regulatory approval in China. SABMiller shareholders would expect to vote on it after that.

AB InBev said the revised terms were final, which means the price is set, and could only be changed if the offer was dropped and another put forward after six months.

Liberum analyst Alicia Forry said she believed the revised bid was likely to be successful by throwing a "small bone" to activist investors and shutting the door to further increases.

"The main thing from ABI’s perspective is they don’t want this to drag and if they engaged (activists) it would," she said.

Bernstein Research brewing analyst Trevor Stirling said SABMiller's shares would probably drop to £41.50 pounds if the bid failed, adding that for AB InBev, an extra $2 bn was only a modest deterioration of a deal that made strategic sense.