Aviva has signed a five year deal to provide protection products for Santander from June 2011.
The deal, which builds on an existing general insurance relationship between the firms, will see Aviva life products available to Santander's UK customer base through its 1,300 branches via telephone and online.
Aviva's core protection products, including life insurance, critical illness and income protection, will now be sold by the Spanish bank which today bought 318 branches of RBS.
"As Britain's leading insurer, our strength lies in the breadth and quality of our product portfolio across both general and life insurance and I'm delighted that Santander's customers will benefit from this," says Aviva chief executive Mark Hodges.
"Our new distribution agreement will build on our solid existing general insurance relationship with Santander, creating a platform for significant growth across our UK business."