US casino operator MGM Resorts has abandoned its bid to acquire its online gambling/sports betting joint venture partner Entain plc, leading to a steep plunge in the latter firm’s share price. 

On Tuesday, MGM issued a statement saying it “does not intend to submit a revised proposal and it will not make a firm offer for Entain.” MGM said it arrived at this decision “after careful consideration and having reflected on the limited recent engagement between the respective companies.” 

The news sparked a massive sell-off of Entain shares, which pushed the price down more than 17% before the panic subsided. Nevertheless, the shares closed out Tuesday’s trading down nearly 12% from Monday’s close. MGM, on the other hand, is currently trading up 3%. 

Early in this new year, MGM publicly expressed interest in acquiring Entain, its partner in the ROAR Digital joint venture, which offers iGaming/betting in multiple US states via the BetMGM brand. After receiving a cooler than expected response to its initial $11b all-stock offer, MGM secured a commitment from shareholder Barry Diller’s InterActive Corp to sweeten the pot by up to $1b in cash.