Rank Group and 888 Holdings have thrown in the towel in their pursuit of William Hill, abandoning a £3.6 billion three-way merger attempt.
The casino giant and online operator had tabled a revised offer for the bookmaker, which was swiftly rejected by William Hill's board on Monday for "substantially undervaluing" the firm.
The firms said they "do not intend to make an offer for William Hill and are withdrawing their proposal for a possible combination of the three companies".
888 chief executive Itai Frieberger added: "We are disappointed that the board of William Hill did not share our vision of the combined businesses. We believe that there was compelling industrial logic for the combination of these highly complementary businesses."
Rank boss Henry Birch added that the deal would have created "significant value for all three sets of shareholders".
888 and Rank Group had said the proposed tie-up would deliver cost savings of £100 million per year and would create the UK's "largest multi-channel gambling operator".
The pair had called on the board of William Hill to begin "constructive discussion" in a bid to reach a deal.
But William Hill chairman Gareth Davis said: "We note the consortium's confirmation that it no longer intends to make an offer for William Hill. We will continue to focus our efforts on our strategy to deliver value for shareholders.
"The team has a clear plan to grow by diversifying digitally and internationally and four priorities to get us there. We have had a good start to the second half of the year and the board now expects operating profit for 2016 to be at the top end of the previously guided £260-280 million range."