LONDON—Iconic Australian brewer Foster's Group Ltd. dropped its resistance to a takeover by SABMiller PLC and agreed to a sale to its U.K. rival for a sweetened price of more than $10 billion.

The deal values Foster's at 5.10 Australian dollars a share, or A$9.9 billion (US$10.17 billion), 4% above what SABMiller offered when it kicked off its pursuit of the company in June. Foster's said Wednesday that as part of the deal, it would return 30 Australian cents a share to its shareholders and that Foster's shareholders owning...