Preheat oven to 300°F. In large roasting pan combine popped corn and pecans. In medium saucepan combine chocolate chips, sugar, corn syrup and margarine. Stirring occasionally, bring to boil over medium-high heat; boil 1 minute.
Pour over popcorn mixture; toss to coat well. Bake 30 minutes, stirring twice. Spoon into 13 X 9-inch baking pan.
Invert onto cutting board. Cut into bars.