The (for now) FTSE 250-listed bookie also confirmed that the relevant Austrian competition authorities issued their clearance.
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The pair expect to obtain the other necessary competition and regulatory approvals in the second quarter of 2021 and possibly as early as the end of March 2021.
The offer was first made in September at 272p per share, a premium of over a quarter compared to the previous closing price.
William Hill and Caesars are already partners in the United States and recently the UK group was included into a tie-up between Caesars and ESPN.
Following the full integration of the Caesars’ sports-books, William Hill will operate more than 170 venues across 15 states, of which the majority will have a mobile presence.
Shares in William Hill rose 1% to 268.4p on Thursday afternoon.