HARRISBURG -- Although several races for the state House remained very close early this morning, Democrats appeared to have increased their control of the House by one vote.

If the results hold up -- and there could be challenges to close outcomes in a couple districts -- Democrats would extend their control of the House to 103-100.

For the past two years, Democrats have controlled the chamber by the narrowest of margins, 102-101.

Democrats appeared to have picked up four seats previously held by Republican incumbents, all of whom are retiring. All four seats were in Philadelphia or its suburban counties.

But one race, in the 157th district in Chester County, Democrat Paul Drucker led Republican Guy Ciarrocchi by only 300 votes out of 30,000 cast. They were vying to replace outgoing Republican Rep. Carole Rubley.

But those Democratic gains were offset by losing three seats, all in Western Pennsylvania.

Rep. Dan Surra of Elk, a member of the House Democratic leadership team, lost to Republican Matt Gabler; Republican Tim Krieger won the seat being vacated by retiring Democratic Rep. Tom Tangretti of Westmoreland; and incumbent Democratic Rep. Vince Biancucci lost his Beaver County seat to GOP challenger Jim Christiana.

Mr. Krieger was leading his Democratic opponent, John Boyle, by only a few hundred votes early this morning. The Biancucci-Christiana race was close also.

Republicans had been hoping to retake the House, which they ran for 12 years before losing control in November 2006.

One seat that didn't change hands is that of House Democratic leader Bill DeWeese of Waynesburg. He overcame a strong challenge for former arena football player Greg Hopkins of Greene County, who also lost to Mr. DeWeese two years ago.

Also, longtime Democratic Rep. Frank Dermody of Oakmont narrowly turned back a strong challenge by Republican Jason Davidek.

While Democrat Boyle was able to capture a northeast Philadelphia seat long held by Republican George Kenney, the GOP held onto another Philadelphia seat.

Longtime Republican Rep. John Perzel, who was House speaker from 2003-06, defeated a challenge from a former Fraternal Order of Police official, Democrat Rich Costello.

Republicans thought they had a good chance of picking up a seat based in Cambria and Somerset counties, where incumbent Democrat Ed Wojnaroski is retiring. But the Democrat, Bryan Barbin, won.

If Democrats do increase their hold on the House to 103 to 100, it could mean the end of the speakership for House Speaker Denny O'Brien, a Philadelphia Republican who has had the job for the past two years.

In January 2007, Democrats chose him as a compromise candidate when Mr. DeWeese failed to muster the necessary 102 votes he needed to become speaker.