Cargill Inc. faces a European Union antitrust probe into its bid for Archer-Daniels-Midland Company's chocolate business over regulators' concerns that the deal could raise prices.

A preliminary investigation showed potential competition concerns over supplies of industrial chocolate in Germany and the U.K., with Barry Callebaut AG the only other main supplier and insufficient competition from smaller companies, the European Commission said in a statement Monday from Brussels.

"The proposed transaction could eliminate an important competitor and reduce the choice of suitable suppliers in already concentrated markets, which could lead to price increases," the commission said.

It set a July 8 deadline to rule on the transaction.

Cargill, the largest closely held U.S. company, last year agreed to buy ADM's chocolate business for about $440 million. The acquisition broadens Cargill's chocolate operations in Europe and particularly production in North America, according to a statement at the time. Included in the sale are plants in Pennsylvania, Wisconsin, Ontario, the U.K., Belgium and Germany.

"The commission needs to complete its process, but we still expect completion of the deal in mid-2015," said Louis de Schorlemer, a spokesman for Minnetonka-based Cargill, in an e-mailed statement. Both companies said they would work with the commission to address its questions.

The deal doesn't involve semifinished chocolate products such as cocoa butter and cocoa powder.

Commodity trader Olam International Ltd. is separately buying ADM's cocoa business for $1.3 billion.