The action was filed by Nordweg Ship Repair at Riga Northern District Court last month, according to information published on the Insolvency Administration's website.
Riga Shipyard CEO Janis Skvarnovics told the LETA news agency he could not comment.
But he said his company had signed a contract for Nordweg to act as a sub-contractor.
The yard has launched a counter-claim.
Last year, Ukrainian company Morski Tehnologii took action against Riga over an alleged debt of more than EUR 120,000 ($165,000).
Morski
