Interbrew is expected to go to the European Court of Justice if it fails in its High Court fight over Bass Brewers.
At 4.30pm on Wednesday (May 23), Justice Alan Moses is due to give his judgement on Trade and Industry Secretary Stephen Byers' decision to block the £2.3bn deal.
During a three-day judicial review from May 9, Interbrew's lawyers attacked Mr Byers' ruling that Bass Brewers must be sold as "grossly disproportionate to the supposed decision".
The minister said he feared Interbrew, which has also bought Whitbread Beer Company, would have an unfair share of the UK beer market.
The Belgian company currently has 12 months from January's decision to find a buyer, who must be approved by the Government.
Interbrew chief executive Hugo Powell (pictured)--> said he hoped the High Court would give it more time to improve the Bass business and sell it at a "reasonable price".
Few companies have been successful in challenging government competition rulings, but the case could be taken to Europe.
Bass Brewers chief executive Iain Napier resigned last week, saying: "As the judicial review process draws to its conclusion, I feel it is an appropriate time for me to move on and pursue other interests."
He has been replaced by Jerry Fowden, who was chief operating officer of Bass' brewing arm from 1994 to 1996.
Mr Powell said: "I am delighted to welcome Jerry back to the Bass organisation. Given his close knowledge of the UK beverage industry, Jerry was a deliberate choice to ensure a smooth transition, stability and continuity at this time."
Mr Fowden quit last month as managing director of Rank's holidays division.
More details on Mr Fowden's appointment:
Former chief returns to Bass Brewers (May 15, 2001)