The initial proposal to the brewer of Peroni and Foster’s beer, made last week, was worth slightly over 40 pounds a share, while its executives and some shareholders regard a deal at closer to 45 pounds as representing a fair value, the people said, asking not to be identified as details of the negotiations aren’t public. A deal at 45 pounds per share would value SABMiller at about 73 billion pounds, and would be the largest merger this year.

London-based SABMiller communicated to AB InBev the terms at which it would be willing to negotiate after the rejection, one of the people said. No final decision has been made on a potential formal offer, and it’s possible the Belgian producer of Budweiser and Stella Artois may walk away from a deal, they said.

SABMiller shares fell as much as 3.9 percent and traded down 2.9 percent at 3,655 pence at 12:24 a.m. in London. AB InBev was little changed at 97.98 euros. Representatives for both companies declined to comment.

Takeover Opposition

The head of The Public Investment Corp., a South African state-owned pension fund manager that is SABMiller’s fourth- largest shareholder, said on Tuesday he opposes a takeover because it could create a brewer that’s too dominant, hurting consumers, as well as potentially removing the company from the Johannesburg stock exchange.

“Quite frankly I’m not in favor of it,” Chief Executive Officer Daniel Matjila said by phone. “We may be creating some kind of a monopoly going forward which may have a serious impact on the global economy and beer market in general.”

Matjila declined to say which way the Pretoria-based PIC, which owns 3.14 percent of SABMiller, according to data compiled by Bloomberg, would vote on an offer should one be made.

Surprise Update

SABMiller on Tuesday released a surprise trading update nine days earlier than planned, in which it announced that beer volume had returned to growth in the second quarter, helped by Africa and Latin America — a trend that could figure into a sweetened offer from AB InBev.

“I don’t think this is a normal type of trading statement, it’s been conveniently brought forward and I don’t think that’s going to be missed by the market given the circumstances,” Javier Gonzalez Lastra, an analyst at Berenberg, said in a phone interview.

If successful, the combination would create a dominant global player in the brewing industry, which has been re-aligned through a decade of increasingly large mergers, and attract heavy scrutiny from antitrust regulators around the world. Controlled by a group of wealthy Brazilian investors led by Jorge Paulo Lemann, AB InBev is itself the result of deals to unite major Belgian, American, and Latin American brewers.

AB InBev had already reached out to Altria Group Inc., SABMiller’s biggest shareholder, before it announced plans to make an approach for its rival, people with knowledge of the matter said on Sept. 18. It’s lining up lenders including Bank of America Corp. and Banco Santander SA to arrange as much as $70 billion in financing for its takeover proposal, people familiar with the matter said last week.

Under U.K. takeover rules, AB InBev has until 5 p.m. on Oct. 14 to make an offer or announce it doesn’t intend to proceed. SABMiller may also ask regulators for an extension to that deadline.