IDFC FIRST Bank has raised $500 million through its maiden international bond issuance, marking the Indian private sector lender's debut in the global debt capital markets.

The offering was priced as 3-year fixed-rate senior notes carrying a coupon of 5.625%, according to a CNBC-TV18 report. S&P Global Ratings assigned the instrument a BBB- rating.

A BBB- score sits at the lowest rung of the investment-grade category on S&P Global Ratings' scale. Senior notes are unsecured debt securities that rank ahead of subordinated obligations in an issuer's capital structure. The investment-grade tag carries practical weight for distribution: many global fixed-income funds are restricted by mandate to investment-grade paper, so the rating determines the pool of investors a deal can reach.

The dollar-denominated sale follows S&P Global Ratings granting IDFC FIRST Bank its first international investment-grade rating, as previously reported by CNBC-TV18.

IDFC FIRST Bank is a Mumbai-headquartered private sector bank formed in December 2018 through the merger of IDFC Bank and Capital First, a non-banking financial company. The lender is led by Managing Director and Chief Executive Officer V. Vaidyanathan, who previously headed Capital First before the merger.

The $500 million raise represents the bank's first tap of overseas bond investors and adds to the range of funding channels available to the institution. Offshore dollar bonds allow Indian issuers to supplement deposits and domestic borrowings and reach global institutional investors that may not hold rupee-denominated debt.