The Fimiston Open Pit gold mine, known as the Super Pit, operated by Kalgoorlie Consolidated Gold Mines Ltd. (KCGM), in Kalgoorlie-Boulder, Western Australia, Australia, on Sunday, August 4, 2024. Photographer: Carla Gottgens/Bloomberg via Getty ImagesBloomberg | Bloomberg | Getty Images Shares in Northern Star Resources rose more than 9% on Monday after the Australian gold miner rejected a proposed $27 billion takeover of South Africa’s Gold Fields, saying the offer undervalued the company. Gold Fields proposed to acquire 100% of Northern Star through a combination of shares and cash, offering 0.3125 Gold Fields shares and A$7.25 in cash for each Northern Star share, according to a Northern Star statement on Monday. Stock Chart IconStock Chart IconNorthern Star Resources Stock. The proposal, received on September 14, initially valued Northern Star at A$38.7 billion ($27.15 billion), representing a 22% premium to its September 11 closing price. Based on Gold Fields’ closing share price on Friday, September 25, the implied value had fallen to A$36.1 billion. Northern Star said its board unanimously rejected the proposal, adding that it “materially undervalues” the company and was “highly opportunistic.” “Gold Fields has sought to acquire one of the world’s largest gold portfolios at a price that is well below what the Board considers its fundamental value and at a very opportunistic time,” said Northern Star Chairman Michael Chaney. The miner also expressed concerns that most of the offer would be paid in Gold Fields shares and that the proposal was subject to several conditions. Northern Star told Gold Fields on Friday that its board did not consider it appropriate to become involved further in the proposal. Bloomberg previously reported that Gold Fields had approached Northern Star about a potential acquisition. Choose CNBC as your preferred source on Google and never miss a moment from the most trusted name in business news.