A 'beer war' after all?

InBev, the Brussels based company that has entered into an agreement to buy Anheuser-Busch, faces a rebellion at last -- coming from a perhaps-unexpected quarter, from Grupo Modelo and allies.

InBev and AB agreed on the terms of their combination in July. Shareholders of the target company are to get a sizeable premium over the price of their stock before the bid, and Budweiser (not Stella Artois) will be the flagship brand of the combined company.

The key fact for understanding the new development is this: AB owns half of the equity in a Mexican beer company, Grupo Modelo, best known for Corona.

GM has initiated an arbitration action against AB, claiming that the latter was obligated under a 1993 agreement to consult it before concluding a deal with InBev. The arbitration action has instigated rumors that what GM really wants is a chance to buy back that 50% share of its equity. But a spokeswoman for the Mexican company denied this to a reporter for Reuters Friday.

InBev has a statement out expressing confidence "that the claims made by Modelo [and related parties] are entirely without merit."

Anyway, if Grupo isn't seeking the opportunity to buy back AB's interest: what does it want? To throw a monkey wrench in the works of the still-unclosed deal entirely? To get a greenmail pay-out for the shareholders who own the other half of its equity? What?

The price of Grupo shares was flat Friday on the Mexican stock exchange. The price of AB shares rose slightly.