Silver miner Hecla Mining Co. said Tuesday its lenders agreed to increase the U.S. company's line of credit to $100 million from $60 million.

The arrangement is effective immediately and represents a new three-year term on the facility, said Hecla, which operates in the U.S. and Mexico.

The financial covenants and interest rate at LIBOR plus 2.75 percent to 3.5 percent, depending on the leverage ratio of the company, remain unchanged. Scotia Capital and ING Capital LLC are the lenders.