MOSCOW (Reuters) – The start of oil products exports from Belarus via Russian ports on the Baltic Sea have been delayed due to disagreements over railway tariffs, three transport industry sources told Reuters on Thursday.

Russia and Belarus signed a three-year agreement last month to re-direct Belarusian oil products to Russian ports, bypassing the Baltic states, in retaliation after the three nations imposed sanctions on top officials in Minsk.

The deal is part of a show of support for Minsk from Moscow following last year’s presidential election, which Alexander Lukashenko said he won but opposition parties in Belarus said was rigged.

Shipments had been initially scheduled to start from March, rising to 3.2 million tonnes next year from 2 million set for this year and amounting to 3.1 million tonnes in 2023.

However, the sources said the flows were unlikely to start this month.

Two transportation sources said railway operator Atlant, which had been designated to bring oil products to the Russian ports from Belarus, has stepped down from the project, saying the tariffs for handling the cargoes were too low.

One of the sources said the transportation rate was offered at less than 1,000 roubles ($13.6) for a railway car per day. That’s comparing to 1,200 roubles on average in Russia.

Another two sources said the contract was also offered to FGK, a subsidiary of the Russian state company Russian Railways. The contract has not been signed and the talks are still under way with FGK and some other operators, they said.

Russian Ministry of Transport, Russian Railways, Atlant and FGK declined to comment.

($1 = 73.7600 roubles)