BERLIN--Insurance company Swiss Re AG says it is in preliminary discussions with Softbank Group Corp. on a potential minority investment by the Japanese technology conglomerate.

Swiss Re said in a brief statement Thursday that "discussions are at a very early stage" and there is no certainty that any transaction will be agreed, when or on what terms.

Zurich-based Swiss Re is one of the world's biggest reinsurers, which provide backup policies to companies that write primary insurance policies.