HNA became a major shareholder in Europe's largest investment bank after acquiring a 4.8% stake in March.
Its financial unit, HNA Capital, reportedly has ambitions of becoming a global investment bank.
Deutsche Bank has been looking to raise funds after incurring major losses due to legal probes and misconduct charges.
Earlier this year, the German lender abandoned plans to sell its Postbank unit and sold 8bn euros ($8.8bn) of shares instead.
HNA, which is privately run by billionaire Chen Feng, has been on a major acquisition spree in recent years.
The Chinese group owns stakes in a range of companies including Hainan airlines, hotel operator Hilton Worldwide and Singapore-listed logistics firm CWT.
Chinese conglomerate HNA has overtaken Blackrock to become Deutsche Bank's biggest shareholder after increasing its stake in the firm to nearly 10%.