EXHIBIT 21

LIST OF SIGNIFICANT SUBSIDIARIES

Anadarko E&P Company LP

     a Delaware limited partnership,

Anadarko Canada Corporation

     an Alberta corporation,

Anadarko Algeria Company LLC

     a Delaware limited liability company,

Anadarko Energy Services Company

     a Delaware corporation,

Anadarko Holding Company

     a Utah corporation,

Anadarko Land Corp.

     a Nebraska corporation,

Headwater LLC

     a Delaware limited liability company,

Howell Petroleum Corporation

     a Delaware corporation