Pennsylvania's two major party candidates for U.S. Senate, Republican incumbent Arlen Specter and Democratic challenger Joe Hoeffel, intend to debate each other once in Pittsburgh and once in Philadelphia.

And that's it.

Until recently, it was uncertain whether the candidates would ever debate face to face.

Specter last month agreed to participate in two debates sponsored by the Pennsylvania Association of Broadcasters, but Hoeffel did not accept the offer right away, complaining that the television organization hadn't bothered to contact him.

The challenger, though, has since agreed to participate in the Pennsylvania Association of Broadcasters debates, which are scheduled to be held Oct. 2 in Pittsburgh and Oct. 9 in Philadelphia.

"We assume they are a go," said David Stone, a media adviser to Hoeffel.

The Democrat, who is struggling to make himself better known to voters in a race against a four-term incumbent, has sought to hold 11 debates with Specter.

But Specter, recognizing that debates could raise his opponent's profile, has consented to participate in only the Pennsylvania Association of Broadcasters encounters.

"We don't have any more [debates] contemplated at this time," said Christopher Nicholas, Specter's campaign manager.

Nicholas said he expects the two debates will be televised on a tape-delay basis.

The Senate race became a little more crowded yesterday when the Libertarian Party submitted the requisite number of signatures to the Pennsylvania Department of State to put candidate Jay Russell on the Nov. 2 ballot.

The Constitution and Reform parties also submitted signatures yesterday, but the department had yet to finish counting by the end of the business day. Yesterday was the state's deadline for submitting nominating petitions.

Hoeffel's campaign team hopes the presence of one or more conservative, third-party candidates on the ballot will siphon votes away from Specter.

"This provides a real alternative for those voters who might come out for President Bush but clearly are not enthusiastic about Sen. Specter," Stone said.

Hoeffel won't gain much benefit from the presence of third-party challengers, Specter's campaign manager countered.

"Joe Hoeffel is still the same unknown, underfunded, far-left candidate he was last week," Nicholas said.