A top European court on Wednesday rejected an appeal by Russian missile-maker Almaz-Antey against EU sanctions imposed for its role in the Ukraine conflict.

As the crisis deepened in 2014, the European Union imposed asset freezes and travel bans on Russian and Ukrainian individuals and entities held responsible for supporting pro-Moscow rebels in eastern Ukraine.

The Luxembourg-based General Court, second only to the European Court of Justice, said it dismissed the appeal because Almaz-Antey had not shown the EU acted disproportionately.

As an arms manufacturer for the Russian government, which "itself supplies weapons to the separatists in Eastern Ukraine, Almaz-Antey materially supports actions which undermine or threaten the territorial integrity, sovereignty and independence of Ukraine," the court said in a statement.

In July 2014, a Malaysian Airlines jet with 298 people on board was shot down over rebel-held territory by what Almaz-Antey later said was likely to have been a BUK missile system similar to those it had stopped making in 1999.

Who ordered the attack remains unknown, with Russia and Ukraine blaming each other.

The General Court said the downing of flight MH17, whether attributed to the rebels or the Ukrainian military, was "irrelevant" to the ruling since it was not decisive in the reasons given by the EU for imposing the asset freeze in the first place.

Shortly after the MH17 tragedy, the EU agreed to impose separate and much more damaging sanctions against key sectors of the Russian economy, including the oil, defence and finance industries.