Munich Re, the world's biggest reinsurer, said on Tuesday it had returned to first-quarter profit after a difficult start to 2011 hit by the devastating earthquake and tsunami in Japan.

The group, which posted a consolidated profit of 780 million euros ($1.0 billion) in the first three months compared to a loss of 947 million euros a year earlier, also slightly raised its full-year outlook.

"Despite the still difficult economic situation, we are optimistic for 2012 and are aiming for a profit for the year of around 2.5 billion euros," Joerg Schneider, chief financial officer, said in a written statement.

The group said that operating profit came to 1.2 billion euros for January to March -- slightly below the 1.26 billion euros expected by analysts polled by Dow Jones Newswires.

In morning trading, stocks in Munich Re were down 1.39 percent to 106.30 euros, with the Dax blue-chip index down 0.72 percent.

Munich Re said at the end of April that it expected first-quarter profits to be "gratifying" amid a calmer situation on the financial markets and fewer losses than last year.