The National Bank of Ukraine (NBU) has launched legal proceedings in both Switzerland and Ukraine against Ihor Kolomoisky, one of the former shareholders of PrivatBank, which was nationalised in late 2016, according to the regulator's statement e-mailed to bne IntelliNews on June 11.

"Both cases concern the enforcement of Kolomoisky's personal sureties given in 2016, in favour of the NBU, to guarantee repayment of the liquidity support loans extended between 2008 and 2015 by the NBU to PrivatBank," the statement reads. In total, these claims seek to recover nearly UAH10bn ($384mn) due under five loan agreements.

The first claim was filed at Kolomoisky's current domicile in Switzerland, before the Tribunal de Premiere Instance in Geneva. The second set of claims was filed at the location of Kolomoisky's property in Ukraine, to the commercial court of the Dnipropetrovsk region.

In December, a UK court ruled to freeze worldwide assets of the former owners, including six companies controlled by Kolomoisky and his partner Hennadiy Bogolyubov, worth more than $2.5bn. According to the NBU, the terms of the voluntary restructuring of the loans of former owners of PrivatBank expired in July 2017, however, the former owners have failed to fulfil their obligations.

Recently, the court ruled that a number of companies associated with former owners’ of Ukraine's PrivatBank — Kolomoisky and Bogolyubov — must provide details on $1.9bn worth of transactions with the lender's funds received from other persons. The companies mentioned in the ruling are Rossyn Investing Corp., Milbert Ventures Inc. and ZAO Ukrtransitservice Ltd, according to Interfax news agency.

At the same time, the oligarchs have challenged its takeover by the state, as well as the NBU's demands to restructure and repay debts to related parties. Kolomoisky and Bogolyubov have filed more than 400 lawsuits against the NBU, PrivatBank and the country's finance ministry.

"The NBU is committed to compelling Kolomoisky to honour the personal guarantees he gave in exchange for the extension of substantial state lending to PrivatBank at the time when it remained under his ownership and control," the statement reads.

According to the regulator, Kolomoisky has shown himself unwilling to honour those guarantees voluntarily, despite the heavy burden that the Ukrainian state has had to bear for his conduct. As the present actions demonstrate, the NBU is committed to pursuing claims against Kolomoisky both in Ukraine and overseas in order to seek to hold him to account.

"These claims are key steps towards protecting the interests of the Ukrainian people and ensuring that PrivatBank’s former shareholders honour the obligations they took on," the central bank's deputy governor Kateryna Rozhkova said in the statement. "PrivatBank received multiple loans from the NBU, with personal guarantees provided by Kolomoisky. It is now clear that, at that time, PrivatBank was not actually able to repay these loans."

She added that in the end, the bank had to be nationalised at great cost to state — the equivalent of 5% of Ukraine's GDP — to protect the interests of millions of account holders and maintain financial stability overall. "The NBU is now taking, and will continue to take, the right actions to seek to recover these outstanding amounts from Kolomoisky," Rozhkova said.

Earlier, the nation's finance ministry published a letter signed by Kolomoisky and Bogolyubov, in which the businessmen committed to carrying out a restructuring programme by mid-2017. If they could successfully restructure 75% of the portfolio, the NBU said it would consider the possibility of extending the restructuring for the remaining 25% until late 2017.

However, a senior NBU official recently told bne IntelliNews on condition of not being identified that the regulator's position in the courts is weak due to the fact that the letter signed by the billionaires has no legal force under Ukrainian legislation.

The fact that Ukrainian businessmen Ihor and Hryhoriy Surkis recently won a legal battle against the bail-in of their deposits of UAH1.1bn (around $40mn) during the nationalisation of PrivatBank adds to the regulator's woes. The funds were deposited at PrivatBank by members of the Surkis family, whom the NBU recognised as alleged related parties of the bank, owned before its nationalisation by oligarchs Kolomoisky and Bogolyubov.

The government nationalised the country's largest lender after it failed to fulfil a three-year recapitalisation plan. The bank was found to have a UAH148bn hole in its balance sheet because of related-party financing.

Earlier, former NBU governor Valeriya Gontareva said the post-nationalisation audit of the bank found that 100% of the corporate portfolio had been made to related parties.