Hitachi Ltd. and Panasonic Corp. are among companies poised to get a European Union antitrust complaint over possible price-fixing of power-storage components used in almost all electrical products from smartphones to refrigerators, people with knowledge of the case said.

Regulators may send a statement of objections to several makers of capacitors before the end of July, said three people, who asked not to be named because the case isn't public.

Margrethe Vestager, the EU's antitrust chief, is making a move on suspected cartels and competition abuses involving some of the world's biggest companies — from Google Inc. to OAO Gazprom — after inheriting unfinished cases when she stepped into the role in November.

The EU is one of several authorities around the world investigating capacitor makers. NEC Tokin Corp. and some subsidiaries were quizzed last year by the European Commission and others, according to Kemet Corp., an NEC shareholder. NEC Tokin was also searched last year by the Fair Trade Commission in a similar probe. The Japanese regulator visited Panasonic's Sanyo Electric Co. and Hitachi Chemical Co. Ltd. offices, among others, including Nippon Chemi-Con Corp.

Masahiko Okamura, a spokesman at Hitachi Chemical Co., said the company is cooperating with earlier investigations in Japan and Europe and declined further comment.

Panasonic spokeswoman Chieko Gyobu declined comment. Representatives for Nippon Chemi-Con, and Kemet didn't immediately respond to requests for comment on whether they expected an EU complaint.

While getting an EU antitrust complaint is usually a precursor for fines, companies that reveal the existence of cartels can escape penalties.

The EU's antitrust complaint would follow a failed attempt to settle the case, one of the people said. Several companies had opposed the settlement, the person said.

"The commission's investigation is ongoing," said Ricardo Cardoso, a spokesman for the authority in Brussels.