Regula is the second longest-serving Republican in the House.
WASHINGTON (CNN) - Rep. Ralph Regula of Ohio, the second longest-serving Republican in the House, will announce Friday that he will retire rather than seek re-election to a 19th term next year, two GOP congressional sources told CNN Thursday.
Regula, 83, a senior member of the House Appropriations Committee and the senior Republican in the Ohio delegation, will make the announcement back home in his northeast Ohio district, the sources said.
The departure of Regula, first elected in 1972, brings the number of GOP House members retiring next year to at least 10, adding additional difficulty to the party's chances of taking back the House in 2008.
In addition to those 10 retirements, another Republican member, Rep. Heather Wilson of New Mexico, is running for the Senate, and Rep. Tom Davis of Virginia is also expected to leave to seek a Senate seat.
Republicans would need to keep those 12 open seats and wrest away at least 16 Democrat-held seats in order to recapture the majority they lost in 2006. And so far, only one Democrat has announced plans to depart - Rep. Tom Allen of Maine, who is running for the Senate.
Although Regula has held a firm grip on his 16th District seat, centered in the Canton area, operatives in both parties expect the race to succeed him to be competitive.
While President Bush carried the district twice, both Democratic Gov. Ted Strickland and Democratic Sen. Sherrod Brown won it in 2006, which was a banner year for Democrats in the Buckeye State.
Anticipating an opportunity, the Democratic Congressional Campaign Committee recruited state Sen. John Boccieri to run for the seat, a Democratic congressional aide said. However, a Republican aide said GOP leaders "were not surprised" by Regula's retirement and have also been reaching out to potential candidates.
- CNN's Deirdre Walsh contributed to this report