MOSCOW (Reuters) — Russia’s top mobile phone operator MTS has doubled its estimated losses from a long-running dispute with Turkmenistan to $1.5 bln, it said on Tuesday.

The company was forced to suspend services in Turkmenistan in 2017 after the state telecoms provider cut it off from its network.

MTS, part of the Sistema conglomerate, filed a request for arbitration against Turkmenistan in July. At that time, it estimated the loss caused by the dispute at least $750 mln.

It made the new estimate as it filed a statement of claim with the World Bank’s International Centre for Settlement of Investments Disputes (ICSID), saying it would “vigorously pursue” its claims in arbitration unless its issues are resolved.