Callon Petroleum Co. (NYSE: CPE) closed its public offering of 40 million common shares for total net proceeds of about $635.2 million.

Callon now has about 201 million common shares issued and outstanding.

Proceeds will support the pending Ameredev acquisition, but if it is not fulfilled, the net proceeds will support exploration and development activities and general corporate purposes.

Underwriters received a 30-day option to purchase 6 million additional shares.

Barclays, Citigroup, Credit Suisse and J.P. Morgan are joint book-running managers.

Callon Petroleum Co. is based in Natchez, Miss.