The Federal Anti-Monopoly Service has opened a case against Sberbank, which is suspected of breaking the law on competition, the service said on its web site Friday.

Following an investigation in the Odintsovo district of the Moscow region, the anti-monopoly service found that Sberbank, Russian Post, a local municipal bank and several providers of communal services colluded to limit the number of ways that Odintsovo residents could make payments for communal services to Sberbank, Odinbank and Russian Post.

Residents could not use other banks to pay for communal services because the service providers put a special barcode on the bills instead of the regular bank details, which gave Sberbank, Odinbank and Russian Post “the ability to affect the conditions of banking services” in the district. The watchdog will review the case Dec. 10 along with the Central Bank. Sberbank had no immediate comment.