Azerbaijan's state oil company Socar is taking legal action in three countries to recover cash from Mubariz Mansimov's tanker company Palmali Group.
Socar said in a statement that it is trying to seize assets controlled by the Turkish shipping company following three arbitration awards in its favour in London in 2020 and 2021.
The company wants the awards recognised and is also trying to win court backing to seize Palmali's and Mansimov's assets.
Details of the legal row have not been made public, but Socar said the dispute arose from "violation of commitments" by the Turkish group and Mansimov.
The two sides "used to have commercial relations previously", although they never had a joint venture, Socar has also said.
The Turkish court of first instance has already ruled in favour of Socar's property claim, Socar added, but Palmali's lawyers appealed.
The Istanbul regional court of appeals upheld the original decision in Socar's favour on 7 October. This decision is final.
Seizures approved
Courts in Azerbaijan and Malta have also approved the seizure applications.
Palmali is listed by Clarksons as owning 23 product tankers and two general cargoships.
The Supreme Court of Azerbaijan has also recognised the arbitration awards, while Turkey and Malta are still considering this.
The most recent arbitration ruling was made in February in London. This awarded more than $132m to Socar, bringing Palmali's bill to $244.5m.
The oil company's Socar Trading subsidiary formed a new shipping arm, United Maritime Logistics, to handle all the state oil group's chartering requirements after it terminated a 10-year-old transport deal with Palmali.
Socar, a major customer, had previously loaned $120m to Palmali.
Trial to go ahead
In May, Palmali was allowed to proceed to trial at the UK High Court in a tanker charter dispute with Russian charter Litasco.
Justice David Foxton permitted the shipping company to amend its claim to pursue $151m in compensation from the unit of Russian energy company Lukoil, down from an original claim of $1.9bn.
A row over the amount of the claim led to a trial set for February this year being scrapped in October 2020, after it had been adjourned from June that year.
The case arose out of contracts of affreightment (COAs) that Palmali argued gave it the exclusive right to carry oil products for Litasco in the Mediterranean, Caspian and Black seas up to a total monthly volume of 700,000 tonnes. The minimum amount was 400,000 tonnes, the shipowner said.
Freed from jail
Turkish media report that Mansimov was released from jail in Turkey in March, after receiving a five-year suspended sentence relating to charges of links to an outlawed organisation headed by Fethullah Gulen, an opponent of Turkish president Recep Tayyip Erdogan.
Palmali has said "there is no evidence to support these false claims", which Mansimov "emphatically denies".
The group is also facing legal action in Malta from Russian lender Sberbank, as it goes after $194m of debt.
Sberbank awarded four loans to two Russian companies, Palmali Caspian Offshore Project and Palmali Company, which were guaranteed by Palmali against vessels allegedly registered in Malta.
