TMX group

CALGARY, July 5 /CNW/ - (TSX - COS.UN) - Canadian Oil Sands Trust (the
"Trust") today announced that its wholly owned subsidiary, Canadian Oil Sands
Limited ("Canadian Oil Sands"), will mail formal documents to reflect its
amended offer to purchase any and all of the issued and outstanding shares of
Canada Southern Petroleum Ltd. ("Canada Southern") (NASDAQ:CSPLF / TSX:CSW) to
all Canada Southern shareholders on Wednesday, July 5, 2006.
These formal documents reflect the increase announced on June 30, 2006 in
Canadian Oil Sands' offer to US$11.10 cash per common share from US$9.75 cash
per common share. Full particulars of the offer are set out in the offer and
circular and related materials, which were mailed to Canada Southern
shareholders on June 26, 2006 and as supplemented by the Notice of Variation
mailed today. These documents are available on the Trust's website at:
http://www.cos-trust.com/investor/.
Canada Southern has announced that its Board of Directors, after
consultation with its legal and financial advisors, and upon receipt of an
opinion from CIBC World Markets Inc., has unanimously determined that Canadian
Oil Sands' revised offer is fair, from a financial point of view, to the
shareholders of Canada Southern and recommends that shareholders accept the
revised offer.

Canadian Oil Sands Limited
Marcel Coutu
President & Chief Executive Officer

Units Listed - Symbol: COS.UN
Toronto Stock Exchange