Renewi PLC (LSE:RWI) shares slumped 21% after Macquarie Asset Management said it was no longer considering bidding for the Anglo-Dutch waste and recycling group.
The giant Australian investment group said: "following multiple attempts to engage with Renewi's board, including a revised proposal, all of which were rejected, it does not feel it is in an informed position to make an offer for Renewi."
Milton Keynes-based Renewi received a 775p cash takeover proposal from Macquarie in September.
At the time, Renewi said the bid "fundamentally undervalues the value of Renewi and its prospects", with the shares having topped 800p within the prop two years.
After the proposed offer was rejected by the Renewi board, the investment arm of the Australian bank went public, turning it into a semi-hostile situation.
One major shareholder advised the London-listed company's board to refrain from discussions with Macquarie unless it increased the offer price, agreeing that it does not reflect Renewi's true value, though other investors disagreed.
Shares in Renewi are down 21% at 520p.