People pass in front of a branch of Deutsche Bank AG in Cologne, Germany. WOLFGANG RATTAY/REUTERS

FRANKFURT/BEIJING － HNA Group Co, the Chinese aviation-to-hotels conglomerate, increased its stake in Deutsche Bank AG to almost 10 percent, overtaking Blackrock Inc as the top shareholder in Europe's biggest investment bank.

HNA's holding in Germany's biggest bank rose to 9.92 percent, according to a regulatory filing on Tuesday by investment entities acting on HNA's behalf.

The conglomerate initially reported a 3 percent stake in Deutsche Bank in February, saying at the time that it may increase its holding, while intending to remain below 10 percent. It disclosed a stake of almost 4.8 percent in March.

Deutsche Bank Chief Executive Officer John Cryan is focusing his attention on returning the lender to growth after grappling with losses resulting from legal probes and misconduct charges. Last month, the bank sold an additional 8 billion euros ($8.8 billion) of shares to bolster capital after abandoning an earlier plan to sell its Postbank unit.

HNA has been on a buying spree, acquiring stakes in Swiss duty-free operator Dufry AG, Singapore-based logistics provider CWT Ltd and hotel operator Hilton Worldwide Holdings Inc.

The Chinese company was reported to have bid for HSH Nordbank, a regional bank in Germany, and earlier this year it took a stake in asset manager SkyBridge Capital through HNA Capital, which has ambitions of becoming a global investment bank and financial-services provider.

BLOOMBERG-CHINA DAILY