BRUSSELS (Reuters) - EU antitrust regulators opened on Wednesday an investigation into U.S. glass maker Corning's exclusive supply deals with mobile phone makers and raw glass processing companies on concerns that these may exclude rival glass producers from large segments of the market.

The European Commission said it would assess whether Corning abused its dominant position in the global market for glass used mainly in mobile phones.

"We are investigating if Corning, a major producer of this special glass, may have tried to exclude rival glass producers, thereby depriving consumers from cheaper and more break-resistant glass," EU antitrust chief Margrethe Vestager said in a statement.

The EU investigation will focus on exclusive sourcing obligations, exclusivity rebates and clauses requiring phone makers to inform Corning about competitive offers and accepting these offers only if Corning fails to match the price, regulators said.

The probe will also look into Corning's deals with companies that process raw glass that include exclusive purchase obligations and no challenge clauses.

The EU competition watchdog said Corning, which sells a break resistant glass used as cover for mobile phones, tablets and smartwatches under the Gorilla Glass brand, may now offer concessions to address its concerns.

Companies risk fines as much as 10% of their global turnover for breaching EU antitrust rules.