BRUSSELS (AP) — The European Union's top court has ruled that calls to companies' after-sales service numbers must not be more expensive than calls to ordinary landline or cellphone numbers.

The European Court of Justice said Thursday that its ruling was necessary to prevent customers being discouraged from using such hotlines to get information on a contract and from asserting their rights.

It was ruling on a complaint against a German company, comtech GmbH, which sells electrical equipment. A German group that fights unfair commercial practices sought an injunction from a Stuttgart court ordering comtech to stop using a hotline number with a prefix that meant calls were more expensive than to a standard number.

The company has since switched its hotline to an ordinary landline.