"We have the fullest confidence in Deutsche Bank's management and will keep a close watch on its future steps and lend support as a shareholder where appropriate," a spokesman for HNA said.
The Chinese aviation and shipping company intends to keep its holding below 10 percent, he said.
HNA's stake of 3.04 percent, worth around 750 million euros (£643 million) at current share prices, makes it the bank's biggest shareholder after Qatar, which has close to 10 percent of stock via two sovereign wealth funds, and BlackRock (BLK.N), which owns 6.1 percent.
Deutsche Bank said it welcomed in principle any investor with a long-term view.
Reporting by Maria Sheahan and Alexander Huebner; editing by Harro ten Wolde and Jason Neely