In June 2005, Paul Manafort pitched a confidential strategy plan to Oleg Deripaska, Russian aluminum magnate and close ally of Russian president Vladimir Putin. In the plan, Manafort planned to open an office in Moscow so he could lead lobbying efforts directed at Western governments, including the US, for the benefit of Deripaska and Putin. The plan would covertly push for Russian interests in the West to bolster the legitimacy of Putin-friendly governments in Uzbekistan, Tajikistan, and Georgia and undercut anti-Russian figures.
Manafort told Deripaska that as part of his work in Ukraine, he worked with legal experts at leading universities and think tanks, including Duke University, New York University, and the Center for Strategic and International Studies, and was lobbying at the highest levels of the US government, including the White House, the US Capitol, and the State Department. (Manafort did not register under the Foreign Agents Registration Act to disclose these lobbying efforts resulting from his work for Ukraine.) Manafort proposed building further relationships with Western journalists to manage communications for pro-Russian parties in the region.
While it appears some aspects of the plan may have been carried out, it does not appear that Manafort opened a Moscow office. Source
In 2008, Paul Manafort formed a partnership called Pericles Emerging Market Partners LP with Deripaska to invest in Eastern European business. With this partnership, Manafort and Deripaska ventured to purchase Ukrainian cable television assets from Black Sea Cable. Deripaska funded the purchase by passing about $20 million through a complex web of Manafort-linked shell companies in tax havens such as the Cayman Islands and Cyprus. However, the deal eventually failed, and it is unknown where the money went, or whether the Cable company’s assets ever even changed hands. Deripaska attempted to recover his investment, but after failing to contact Manafort or his partner Rick Gates, Deripaska filed a lawsuit in the Cayman Islands against Manafort’s company to attempt to recover debt Manafort owed him of about $17 million.
In 2014, Oleg Deripaska sued Manafort’s company, trying to recover his investment relating to Black Sea Cable. In late 2015, a few months before Manafort joined the Trump campaign, Deripaska stopped pursuing this action. Source1 Source2
A large cache of Manafort’s emails was obtained as part of the Mueller probe into the Trump-Russia conspiracy. These emails included correspondence between Manafort and Konstantin Kilimnik, a Ukrainian employee of his consulting practice who once served in the Russian army. Kilimnik was suspected of having ties to Russian intelligence and was a person of interest in the Senate Intelligence Committee investigation into Trump–Russia collusion. Source In one email from Manafort to Klimnik dated July 7, 2016, Manafort offered to provide Deripaska with private briefings on the US presidential race. It is not known whether the briefing took place. In the emails, Manafort also expressed his desire to use his new notoriety from his new position as Trump’s campaign manager to collect past debts. These and other emails between Manafort and Kilimnik were written using veiled language and what appeared to be code words. Source
The Black Sea Cable transaction is among many such dealings being investigated as allegedly being part of a corrupt scheme to enrich Yanukovych and his allies, including a palatial presidential residence with a private zoo, golf course, and tennis court. Source It kind of looks like Manafort defrauded Deripaska on Yanukovych’s behalf. On the other hand, the news reports discussed above may be based primarily on Deripaska’s complaint, which is probably not factually accurate.
Note that when Manafort joined the Trump campaign he had $17 million in debt to Deripaska, which is the same amount he admitted in 2017 to have received in payments from the Party of Regions. It’s not clear but it appears Manafort may have utilized his position in the Trump campaign to persuade pro-Russian parties to pay off his debts to Deripaska, causing Deripaska to drop his lawsuit against Manafort.