Profits at Germany's biggest lender Deutsche Bank tumbled in the third quarter, the group said Wednesday, but its chief executive said the long-troubled institution was on its way back to profitability.

Net profits at the Frankfurt-based group fell 65 percent year-on-year between July and September, to 229 million euros ($262.7 million), short of analysts' forecasts of a 240-million-euro bottom line.

The group highlighted a fatter operating, or underlying, profit of 506 million euros, but that figure was still 46 percent below the third quarter of 2017.