AMSTERDAM (Reuters) - Vodafone's Dutch subsidiary said on Friday it had sold fixed-line operations with around 150,000 customers to Deutsche Telekom subsidiary T-Mobile Nederland for an undisclosed sum.

Vodafone agreed to sell the operations as a concession to European Union regulators in order to gain approval for the larger merger of Vodafone's Dutch operations with Liberty Global's Dutch subsidiary Ziggo.

Vodafone is the second-largest mobile provider in the Netherlands, while Ziggo is the biggest cable company.

Together they are expected to form a strong competitor to KPN, the former Dutch state telecommunications company.

(Reporting by Toby Sterling; editing by Jason Neely)