VILNIUS, April 24 (Reuters) - Lithuania will make a decision on whether to withdraw from a treaty governing the common power grid of Russia, Belarus and the three Baltic States by Aug. 6, based on a review of studies into the potential impact, its energy minister said on Monday.

Estonia, Latvia and Lithuania, all members of NATO and the European Union, remain a part of the Soviet-era BRELL circuit with Russia and Belarus, relying on Russian operators to control frequencies and balance the grid.

The three countries signed a deal in 2018 to decouple from the BRELL circuit and join the continental power grid by 2025, but Lithuania wants to leave in the first part of 2024. Neither Latvia nor Estonia has yet agreed to an earlier decoupling.

Energy Minister Dainius Kreivys told reporters Lithuania will make its decision to withdraw after reviewing the results of three studies into the preparedness of the Baltic power grids to decouple from BRELL by the earlier date.

The studies, by power grid operators of the Baltic States and Poland's Institute of Power Engineering, are due to be completed by late May, Lithuania's power grid operator Litgrid said.

Kreivys said the results of the studies could also lead the other Baltic states to agree on an earlier decoupling from Russia.

"We are doing these studies at the request of Latvia and Estonia. We have agreed that, if the results are positive, we can decouple earlier… We believe they will be positive," he said.

Estonian Prime Minister Kaja Kalas told Reuters on April 12 her country could support faster decoupling, but only if it is convinced the Baltic grid is fully prepared to work on its own.

Last June, Reuters reported European grid operators are ready to implement immediately a long-term plan to bring the Baltic states, which rely on the Russian grid, into the European Union system in the event Moscow cuts them off. (Reporting by Andrius Sytas in Vilnius)