The proposed sale of Seagram's drinks brands to Pernod Ricard and Diageo is not expected to be completed until later this year.
Pernod Ricard chairman Patrick Ricard said the buyers originally hoped to begin integrating their acquisitions in April.
But the £5.5bn deal, agreed in October last year, is still in the hands of competition authorities in Europe and the United States.
According to press reports, this means that Pernod Ricard's PR Brands UK and Diageo's Guinness UDV are unlikely to get their hands on any brands until later this year.
Seagram Drinks, which continues to handle its brands in the UK until the proposed deal is completed, is being sold by media group Vivendi Universal, which was created in a merger with Seagram.
Pernod Ricard wants Martell cognac and Chivas Regal and Glenlivet whiskies, while Diageo's Guinness UDV is believed to be after Myers and Captain Morgan rums and Crown Royal Canadian whisky.
Vivendi is understood have put Seagram's 246-strong off-licence chain, Oddbins, on the market to raise about £65m.
Possible buyers include Nomura Principal Finance Group's First Quench, which owns Victoria Wine and Thresher, and Nader Haghighi's Parisa Group.