The partnership marks Reliance's foray into the credit card space and comes months after Ambani separately listed its financial services business as it seeks to diversify its already sprawling oil-to-retail business.

SBI Card could lure customers with access to rewards across Reliance Retail's 18,650 stores in India, at a time when credit card spending has boomed.

The ongoing festive season, when customers make most big-ticket purchases, is also expected to boost spending.

Data from the Reserve Bank of India showed credit cards in the network had surged nearly 20% year-on-year as of September.

SBI Card, India's no.2 credit card issuer majorly owned by top lender State Bank of India, will launch two variants of the card with Reliance Retail, which owns brands, including Reliance Digital, JioMart and Netmeds.

(Reporting by Chris Thomas in Bengaluru; Editing by Sohini Goswami)