Combine chocolates in top of a double boiler; bring water to a boil. Reduce heat to low; cook until chocolates melt, stirring frequently. Remove from heat, and let cool.
Line a buttered 8-inch square pan with a 7-inch-wide strip of aluminum foil, allowing foil to extend 3 inches over 2 sides of pan. Butter foil.
Beat margarine at medium speed of an electric mixer until creamy; gradually add sugars, beating well. Add eggs, one at a time, beating just until yellow disappears. Add liqueur, vanilla, and orange rind; beat well. Add melted chocolate, and beat at low speed until blended. Add flour and salt; beat at low speed until blended. Stir in pecans.
Spoon mixture into pan. Bake at 350° for 18 minutes or until a wooden pick inserted 2 inches from the edge comes out clean. Cool in pan on a wire rack. Cover and chill at least 4 hours. Using aluminum foil handles, lift brownies out of pan. Cut into squares.