The biggest German bank, Deutsche Bank, posted on Tuesday a second quarter net profit of 1.2 billion euros ($1.7 billion), after taking an impairment charge of 155 million euros related to the Greek debt crisis. The bank''s net result, which marked an increase of 6.2 percent from the same period in 2010, was better than an average analyst forecast of 1.03 billion euros compiled by Dow Jones Newswires. The German bank said its total exposure to debt in Greece, Ireland, Italy, Portugal and Spain stood at 3.7 billion euros as of June 30. Core income before taxes in the three months from April through June rose to 1.8 billion euros, a gain of 17 percent on the year. Deutsche Bank took 464 million euros in provisions against risky loans in the quarter meanwhile, compared with 243 million a year earlier. The bank''s core Tier 1 ratio, a measure of its ability to withstand unexpected shocks to the financial sector, gained 1.5 percentage points to a healthy 10.2 percent. "Despite increasingly difficult market conditions, our business model has proven to be robust," chairman Josef Ackermann was quoted by a statement as saying. "Our efforts to recalibrate and rebalance our platform are paying off nicely," he added in reference to the bank''s acquisition of Postbank, which has Germany's largest retail banking network.