Investors in the trans-Tasman food giant are being offered 70 New Zealand cents per share by the Singapore agribusiness in conjunction with the Hong-Kong listed investment business, First Pacific Company.
But Goodman Fielder says the offer is opportunistic and materially undervalues the company, whose brands include Meadowlea, Praise, Vogels and Edmonds.
Shares in Goodman Fielder are trading at 71 New Zealand cents, up from 57.5 cents on Friday.
The offer from Wilmar International, which holds 10.1 percent of the company and First Pacific, came in over the weekend.
Goodman Fielder says the offer is non-binding and highly conditional.
Wilmar wants to use a scheme of arrangement, which means it needs acceptance from shareholders who own at least 75 percent of the company, and they must number at least half the shareholders.
The arrangement also covers all classes of securities, such as debt.
Goodman Fielder has $NZ250 million n bonds set to mature in May 2016, so the merger would also need approval from bondholders.
This type of takeover is an easier way to acquire a listed company than a normal takeover which needs 90 percent of shareholders to accept.
The conditions include due diligence, unanimous recommendation by Goodman's board, and approval by the boards of Wilmar and First Pacific.
But Goodman's board has told Wilmar and First Pacific that the proposal undervalues the company.
Goodman says it wants to maximise shareholder value and would consider a more realistic offer.
In the meantime, Goodman Fielder says it's committed to cutting costs and it continues to explore its options for its New Zealand dairy business.