Last checked at 
(Adds O2 CR reaction)
BRUSSELS, Oct 25 (Reuters) - The European Commission said onTuesday it is to investigate whether a mobile telecomsnetwork-sharing deal between O2 CZ/CETIN and T-MobileCZ restricts competition in the Czech Republic.
The cooperation between the two companies, which serve aboutthree-quarters of the Czech market, started in 2011 and hadsince been increased in scope to include 3G and 4G data servicesand covers all of the country with the exception of Prague andBrno.
The Commission said it would investigate whether the deal slows down quality improvements in existing infrastructure ordelays the deployment of new technologies as well as newservices based on them.
The country's only other mobile network operator is Vodafone, the smaller of the three, which is not party to thenetwork-sharing agreement.
O2 CZ/CETIN and Deutsche Telekom unit T-Mobile CZmay have to end their arrangement or modify it if found to be inbreach of EU competition rules.
CETIN is a telecommunications infrastructure firm that wasspun off from O2 Czech Republic last year. Its owner is Czechbusinessman Petr Kellner's investment group PPF, which also ownsover 84 percent of the shares in O2 Czech Republic. No one atCETIN could immediately be reached for comment.
O2 Czech Republic said that networking sharing was aEuropean trend and partnerships seen in countries such asBritain, Sweden or France showed the concept worked.
It said the deal allowed it to invest in new services andproducts.
"O2 is keeping its critical network infrastructure whichdetermines the service quality and customer experience. Ofcourse, O2 has its own absolutely independent businessstrategy," the company said.
T-Mobile CZ also said the network-sharing deal was positivefor customers.
"We are closely cooperating with the European Commission inthe given matter," a spokeswoman said. "We are convinced thatcooperation in the area of network sharing does not curbcompetition nor innovations. On the contrary it brings benefitsto end-customers." (Reporting by Foo Yun Chee; Additional reporting by Jan Lopatkain Prague; Editing by Robert-Jan Bartunek, Greg Mahlich)
