GENEVA, Oct. 21 - Ukraine launched its first trade dispute against Russia at the World Trade Organization with a complaint about restrictions on Ukrainian-made railway equipment, the WTO said on Wednesday, according to Reuters.

"Ukraine claims that since late 2013, the conformity assessment certificates for railway products imported from Ukraine into Russia have been suspended without any explanation and new applications have been rejected," the WTO said in a statement.

Ukraine alleged that the restrictions broke several WTO rules and amounted to an effective ban on imports of the products into Russia, the WTO statement said.

Ukraine, which has been battered by an 18-month war with pro-Russian separatists backed by Moscow, maintains that the Russian measures break a range of WTO rules.

Kiev's request for consultations marks the first step in the WTO dispute system, which requires that the parties begin talks within 30 days.

If the consultations fail, the WTO, which polices global trade accords in an effort to ensure a level playing field for its member economies, can create a panel of experts to review the case.

Locomotives, rolling stock and other railway equipment were Ukraine's most valuable export to Russia in 2011, accounting for $3.2 billion out of a total of $19.8 billion of export sales to Russia in that year.

But the value fell by one-sixth in 2012, a further one-third in 2013, and then another two-thirds in 2014, when railway exports to Russia were worth just $601 million, according to data from the International Trade Centre, a U.N.-WTO joint agency.

Russia remains by far the biggest customer, followed by Kazakhstan and Belarus, whose purchases from Ukraine have also plummeted. Kazakhstan and Belarus are Russia's fellow members of the Eurasian Economic Union trading bloc, but neither is a WTO member, so Ukraine cannot sue them at the Geneva trade body.

Trade friction between Russia and Ukraine, as well as the Kiev government's allies in Washington and Brussels, has worsened since the ouster of former Ukrainian President Viktor Yanukovych and Russia's annexation of Crimea.

The case is the sixth to be brought against Russia since it joined the WTO three years ago. Details will be posted on the WTO's website in the next few days.

Under WTO rules, Russia has 60 days to settle the dispute. After that, Ukraine could ask the WTO to adjudicate.

Wednesday's complaint was the first filed by Ukraine since it became a WTO member in 2008. (rt/afp/ez)