Brazil's Bradesco may buy stake in insurer-report

* Bank would become No. 2 shareholder in Porto Seguro

* Bradesco spokeswoman declines to comment

SAO PAULO, June 30 (Reuters) - Brazil's second-largest private-sector bank, Bradesco (BBDC4.SA), is in talks to buy a minority stake in insurer Porto Seguro seeking to prevent rivals from gaining a foothold in the last independent insurer in the country, a local newspaper reported on Tuesday.

An agreement with Porto Seguro (PSSA3.SA), the country's largest automobile insurer, would position Bradesco as the second-biggest shareholder in the company, after controlling shareholder Jayme Garfinkel, Valor Economico reported, without saying how it obtained the information.

Bradesco ranks as the top insurance group in Brazil and third-largest auto insurer.

A Bradesco spokeswoman declined to comment on the Valor story. Porto Seguro did not immediately return calls seeking comment.

Garfinkel isn't considering relinquishing control of Porto Seguro, of which his family owns about 57 percent, Valor said.

As part of the transaction, Bradesco would receive Porto Seguro shares in exchange for ceding its car insurance portfolio to the company, Valor said, citing an unnamed analyst.

Porto Seguro's market capitalization is currently 3.4 billion reais ($1.73 billion). (Reporting by Guillermo Parra-Bernal; editing by John Wallace)