The offer has already been snubbed by the board of SABMiller, saying the 42.15 pounds per share valuation was "very substantially" under par.

"We have confidence in the board and we will rely on their judgment. They have said the price is too low and we agree with them," said Dan Matjila, chief executive of Public Investment Corporation (PIC), which owns about 3 percent of SABMiller.

The rejection by the PIC, as well the board, is testing the determination of AB InBev to create a $280 billion global brewing giant that would control about one third of world's beer market just days before Wednesday's bid deadline.

The brewer of Budweiser and Stella Artois may raise its offer to as much as 44 pounds per share, source close to the matter told Reuters on Sunday.

The PIC, which manages more than $120 billion in South African government employee pensions, also needed more details on the AB InBev's proposed secondary listing of the combined brewer on the Johannesburg's bourse, Matjila said.

"It may not be in our best interests to liquidate a blue chip counter on the JSE without clearly understanding how that money finds its way back to JSE," he said.

A Johannesburg listing of the combined entity, as SABMiller is, is one of the key consideration for South Africa-based funds because they are required to limit their exposure to international stocks.

(Editing by James Macharia)

By Tiisetso Motsoeneng

Stocks treated in this article : ANHEUSER-BUSCH INBEV, SABMiller plc
Valeurs citées dans l'article : ANHEUSER-BUSCH INBEV, SOUTH, SABMiller plc