Bristol-Myers Squibb Co. and its Mead Johnson Nutrition unit sued Abbott Laboratories, claiming Similac infant food is sold in packages they developed.

The new Similac SimplePac packages infringe a patent for a "container and scoop arrangement" issued in May 2006, Bristol Myers and Mead said in the complaint filed Monday in federal court in Evansville, Ind. They want cash compensation and an order that Abbott stop selling Similac in the new containers.

The SimplePac, billed as "the most mom-friendly package ever introduced," has a hinged top with a scoop in the lid.

Abbott, based in North Chicago, began selling Similac with the new packaging last month.

"Abbott independently designed its new packaging and launched the SimplePac package after conducting extensive research with more than 1,600 mothers to ensure that it meets their needs," spokesman Scott Stoffel said.