By Mauro Orru

Cattolica Assicurazioni SC's shares jumped Thursday after Assicurazioni Generali SpA committed to becoming a major shareholder.

Generali said late Wednesday that Cattolica would approve by July 15 a capital increase of 300 million euros ($337.5 million) for Generali to secure a 24.4% stake.

At 0745 GMT, Cattolica shares were trading 34% higher at EUR4.83.

Cattolica is also set to approve a second tranche of EUR200 million of the capital increase, open to all shareholders.

Generali said the subscription of the EUR300 million capital increase requires adoption by Cattolica of the Societa per Azioni status, effectively transforming it into a joint-stock company.

"The transformation into joint-stock company and the presence of Generali as major shareholder strengthen the medium term speculative appeal of the stock," Andrea Lisi, analyst at Italian investment bank Equita Sim, said.

James Shuck, analyst at U.S. bank Citi, said the planned debt raise would help Cattolica to address its solvency position, which has fallen below regulatory minimums in a key subsidiary.

The share capital increase stems from a newly launched partnership spanning governance and commercial agreements between the two insurers.

The two companies will collaborate in asset management, the internet of things, health business and reinsurance.

"For Generali, this gives access to 3.5 million Italian customers and 1,400 agents, at what we see as a very attractive price," Mr. Shuck said. 



  Write to Mauro Orru at mauro.orru@wsj.com; @MauroOrru94