EU regulators are planning to impose fines on three firms -- Philips, South Korea's Samsung Electronics and Germany's Infineon Technologies -- for allegedly fixing the prices of microchips used in mobile SIM cards.
The chips are also used in bank cards, identity cards, passports and in television systems.
The European Union's antitrust arm has charged the firms with operating a cartel and the companies could be fined in late July or in September, an unnamed source told Reuters.
Pursued by the news agency, officials with the European Commission (EC), Philips and Infineon refused to comment. Samsung officials were not available for comment.
Companies that break EU rules can be fined up to 10% of their worldwide turnover. Dutch firm Philips's 2013 turnover stood at €23.3bn ($31.72bn, £18.71bn).
The chipmakers had initially sought to settle the case, which means they plead guilty in return for a 10% reduction in sanctions, but talks collapsed in 2013.
The likely fines follow raids on the companies' European offices, by the EC, in December 2013 and in October 2008.