July 17 (Bloomberg) -- Allianz SE, Europe's biggest insurer, rose the most in four months in Frankfurt trading after Boersen-Zeitung reported the company will make a decision tomorrow on the sale of its Dresdner Bank unit.

Munich-based Allianz gained as much as 6.2 percent to 107.30 euros, the biggest increase since March, and was trading at 105.83 euros at 10:11 a.m. The insurer's shares have declined 28 percent this year, valuing it at 48 billion euros ($76 billion).

Dresdner's supervisory board will gather for a meeting tomorrow when a decision by Allianz on ``exiting'' the bank is expected, Boersen-Zeitung said. A combination of Dresdner with Commerzbank AG is ``the most likely scenario,'' the German newspaper said. Allianz Chief Executive Officer Michael Diekmann has said Europe's largest insurer is in talks that might lead to a sale or merger of Dresdner.

``The market is relieved that the sales process is moving forward,'' said Thilo Gorlt, a Frankfurt-based analyst at BHF- Bank AG, who recommends investors buy the stock.

Commerzbank, Germany's second-biggest bank by assets, gained 1.02 euros, or 5.5 percent, to 19.72 euros.

To contact the reporter on this story: Aaron Kirchfeld in Frankfurt at akirchfeld@bloomberg.net.

Last Updated: July 17, 2008 04:34 EDT