B2Gold (BTG) late Wednesday disclosed plans for $350 million offering of convertible senior unsecured notes maturing in 2030.

Interest rate and initial conversion price for the notes will be determined later. The company is providing the initial purchasers with a 15-day option to buy up to $52.5 million of additional notes.

It also plans to enter into a cash settled total return swap for up to $50 million of shares with one of the initial purchasers to protect existing shareholders from dilution if the new notes are converted into shares.

Net proceeds from the offering will be used for working capital requirements and for general corporate purposes. The miner also plans to apply a portion of the net proceeds to pay down the outstanding balance for its revolving credit facility.

B2Gold shares were sinking 7% in recent extended trading.