WASHINGTON (AP) _ Johnny Isakson, one of the pioneers of the modern Georgia Republican Party, took the oath of office today to succeed former House Speaker Newt Gingrich as congressman from the state's 6th District.

Speaker Dennis Hastert, R-Ill., administered the oath to the veteran state legislator in a brief ceremony on the House floor. Both Hastert and Isakson were the beneficiaries of Gingrich's decision to resign from Congress after the poor showing by the GOP in last fall's election.

``I am well aware that to all of you I am nothing more today than the fellow that replaced Newt,'' Isakson told his new colleagues. ``I hope in the years to come I'll be a respected friend and one who joined with you to make a difference for the United States of America.''

Isakson, who has a long history of cooperating with Democrats in Georgia, defeated six other candidates Tuesday to win a special election to succeed Gingrich, one of the most partisan speakers in recent history.