Canadian Superior Energy Inc., Calgary, (Toronto, Amex: SNG) has increased its offer for Canada Southern Petroleum Ltd., Calgary, (Toronto: CSW; Nasdaq: CSPLF) to US$14.97 per share (C$17.10) for a total deal value of US$217 million (C$248 million). Canadian Superior had previously offered US$13.28 per share (C$14.93). Canadian Oil Sands Ltd., a subsidiary of Canadian Oil Sands Trust, Calgary, (Toronto: COS.UN) was the previous high bidder with a US$13.10-per-share offering valued at US$190 million.