In an extraordinary turn of events, the German city of Hanover is preparing to file a law suit to stop the Belgian beer giant Interbrew from buying Gilde Brauerei.

Interbrew announced a €525m deal on Friday to acquire Brauergilde Hannover, the parent company of the German brewer. Interbrew also offered to buy the 14.6% of Gilde that Brauergilde Hannover did not own, once the first deal had been completed.  

However the German city of Hanover is taking Brauergilde Hannover to court over the company's decision on Friday to accept the offer. It says the German brewer failed to get its sale to Interbrew approved by enough shareholders.

Although more than 60% of Brauergilde Hannover shareholders attended an extraordinary meeting on Friday and voted in favour of changing the company's by-laws to allow for its sale to Interbrew, the city is arguing that a simple majority was enough to approve the sale.

The city treasurer said: "For a change in the company status to allow a takeover in the first place, a 75% majority is needed. There was no 75% majority, but only a simple majority."

The city's decision to delay or block the takeover, which was originally invited by the supervisory board of Gilde, is being seen as a move to protect jobs in the capital of Lower Saxony.

But reports suggest that Interbrew was chosen in the first place as the preferred bidder, over rival bidders SABMiller ad Heineken, because of comprehensive guarantees that jobs wouldn't be cut.