The move makes no difference to the total enterprise value of the deal, including debt, which remains at A$11.5 billion (7.3 billion pounds) and will not change the total cash received by Foster's shareholders.
The shareholders will now get the 30 cents payment, worth some A$582 million in total, via the higher SABMiller cash offer rather than through a Foster's capital return.
SABMiller share were off 1.1 percent at 2,167 pence at 9:05 a.m. British time in a London stock market around 0.8 percent lower.
The two firms in September agreed a cash deal at A$5.10 a share valuing Foster's at A$9.9 billion (6.29 billion pounds), and under that deal, the Melbourne-based Foster's would have made the 30 cents a share capital return.
The takeover requires approval of 75 percent of votes at a Foster's shareholder meeting in December. The deal has wide support from institutional investors.
SABMiller expects its biggest ever takeover deal to close by the end of the year and put it at the head of the Australian beer market with a near-50 percent share.
The deal is part of its strategy of creating an attractive global spread of businesses to add to its operations largely in the emerging markets of Africa, Latin America, Asia and Eastern Europe, but also in developed markets like the United States.
The London-based brewer of Peroni, Miller Lite and Grolsch launched its initial bid for Foster's at A$4.90 a share, on June 21 and then went hostile by taking the offer direct to shareholders at the same price on Aug 17, but Foster's rejected both as being too low.
Peace broke out in the acrimonious three-month bid battle after SABMiller offered to raise its cash bid to A$5.10, and Foster's shareholders would get the capital return and keep Foster's final dividend of 13.25 cents.
Foster's, the maker of Victoria Bitter, Carlton Draught and Pure Blonde, has been struggling with declining volumes as demand for traditional beers falls, and its market share has fallen to 50 percent from 55 percent.
Foster's has retreated back into Australia giving up its global beer empire and split its wine business paving the way for a sale of the beer business that still boasts high profit margins.
(Reporting by Narayanan Somasundaram and David Jones; Editing by Lincoln Feast and Mike Nesbit)