Germany’s largest bank, Deutsche Bank, yesterday posted a steep third-quarter loss linked to its purchase of Postbank, but said underlying operating results were stable.

Deutsche Bank reported a net loss of €1.2 billion that included a one-off charge from its takeover of Postbank, a deal meant to broaden Deutsche Bank’s revenue base.

Analysts polled by Dow Jones Newswires had forecast a deeper net loss of €1.47 billion, and Deutsche Bank shares leapt higher in morning trading on the Frankfurt stock exchange.

They gained 2.11 per cent to €42.06, while the DAX index was 0.09 per cent higher overall.

The bank warned in September that it would incur a charge of €2.3 billion as part of a re-evaluation of its holding in Postbank, which has Germany’s largest retail banking network.

The new calculation was required because Deutsche Bank has offered to buy all of the shares in Postbank in a bid to raise its stake from nearly 30 per cent to more than 50 per cent by the end of this year.

Excluding the Postbank charge, Deutsche Bank posted a net profit of €1.1 billion in the three-month period, down from €1.4 billion in the third quarter of 2009.

The bank reported net revenues of €5 billion including the charge and a pre-tax operating loss of €1 billion.

Without the charge, Deutsche Bank posted a pre-tax operating profit of €1.3 billion, the same amount as in the third quarter of 2009.

A statement quoted chairman Josef Ackerman as saying: “The third quarter results again prove the robustness of our recalibrated business model despite the difficult ongoing macro-economic and market conditions.”

Deutsche Bank is buying Postbank to add a strong retail banking pole to its traditional investment bank activities.

Those still contributed the most to overall results however, with net revenues of €4.1 billion, which Deutsche Bank finance director Stefan Krause called “pretty remarkable” during a telephone press conference.

Recent results by rivals like Credit Suisse, UBS and Goldman Sachs have disappointed markets.

Other Deutsche Bank divisions helped overall earnings as well following the acquisitions of wealth management firm Sal Oppenheim and parts of the Dutch bank ABN Amro last year.

“We are on the path to reaching good results in 2010,” Krause said, though he did not provide details.

Early this month, Deutsche Bank raised €10.2 billion, its biggest capital increase ever, to finance the Postbank takeover and reinforce core capital in view of proposals from international banking regulators.

“Our retail banking operation is vastly increasing its footprint in Germany, which will balance our earnings towards an even more stable business,” Ackermann said.

The bank booked €362 million in loss provisions in the quarter, less than the €544 million recorded in the same period of 2009 but more than the €243 million seen in the second quarter of 2010.

It reported a Tier 1 capital ratio of 11.5 per cent and a core Tier 1 ratio of 7.6 per cent, and aims to meet so-called Basel III guidelines being drafted to ensure banks are not vulnerable to another financial crisis six years ahead of schedule.

Deutsche Bank did not provide an outlook for the full year, but has already targetted a pre-tax profit of €10 billion in 2011.