NORTHFIELD, ILL. — Kraft Foods Group Inc. in a May 2 filing said it is being investigated by the Commodity Futures Trading Commission over activities related to the trading of December 2011 wheat futures contracts. The activities arose prior to Kraft’s spin-off from Mondel?z International in September 2012 and involve the business now owned and operated by Mondel?z or its affiliates.

“We are cooperating with the staff in its investigation,” Kraft said in the filing. “While the staff has advised us that they are prepared to recommend that the Commission consider commencing a formal action, we and Mondel?z International are seeking to resolve this matter prior to any formal action being taken.”

The business involved in the trading now is owned by Mondel?z, and according to Kraft, Mondel?z will bear most of the costs and any monetary penalties or other payments that the C.F.T.C. may impose.

“We do not expect this matter to have a material adverse effect on our financial condition or results of operations,” Kraft said.