Telecommunications carriers — Bharat Sanchar Nigam Ltd and Mahanagar Telephone Nigam Ltd — signed a pact on Tuesday to share infrastructure and provide joint services to corporate customers.

BSNL operates mobile, fixed-line and Internet services in 20 of India's 22 telecommunications zones, while MTNL operates in Delhi and Mumbai zones. Hit by intense competition from private sector rivals, both carriers have seen their market share eroding, and lost money in the past four fiscal years.

The two carriers will share assets like buildings, mobile masts and international long-distance phone networks.