Google bought Motorola Mobility in 2012.
The commission criticized Motorola Mobility Monday for patent abuse in seeking an injunction against Apple in Germany, The New York Times reported.
Motorola Mobility had alleged it owned sole rights to a "standard essential" patent that is part of GSM mobile, which is the telecommunications system used in Europe, the Times said.
"I think that companies should spend their time innovating and competing on the merits of the products they offer -- not misusing their intellectual property rights to hold up competitors to the detriment of innovation and consumer choice," said the European Union's commissioner for competition, Joaquin Almunia.
When Google acquired Motorola Mobility, the European Commission warned the company that Google could be held liable for patent abuses Motorola Mobility may have committed.
Google did not comment on Monday's preliminary finding, which could lead to formal antitrust charges, the Times said.