Sources: Negotiations on open-wheel merger continuing

Constituents with a stake in American open-wheel racing are still waiting to see if the most advanced discussions to date between the Indy Racing League and the Champ Car World Series result in the two groups racing under one umbrella in 2008 and beyond.

High-level sources from both series confirmed to ESPN.com that negotiations continue. But with the IndyCar Series opener at Homestead-Miami Speedway only 41 days away, time is becoming a critical factor.

"If something is going to happen it will have to be soon," noted an emissary with inside knowledge of the talks.

Progress has been hampered by the fact that two of the key figures involved in the process have been or will be out of the country. IRL founder Tony George was expected to return to the United States on Sunday from London, where he traveled to attend 2003 IndyCar Series champion Scott Dixon's wedding. Meanwhile, Champ Car co-principal Kevin Kalkhoven left for his own three-day trip to England on Sunday to attend a family function.

"We continue to see advantages in a merger with the IRL," Kalkhoven said prior to his departure. "Equally, we are quite happy to go it alone. At the moment, we're going Champ Car racing."

It is believed the two competing race series have reached an agreement in principle to work together and lawyers are toiling to hammer out the details for final approval. But several key issues, including the date for the IndyCar Series race at Twin Ring Motegi in Japan and the level of support that will be given to teams, remain unresolved.

"Things are progressing, but [the process is] delicate and complicated," George told ESPN.com in an e-mail.

The nine teams that expected to compete in Champ Car this year are in limbo, awaiting information whether they will have to frantically gear up to race in the IndyCar Series. Champ Car's Panoz chassis and turbocharged Cosworth engines are not compatible with the IRL's single-seat formula, which utilizes a chassis made by Italian firm Dallara and normally aspirated Honda engines.

Meanwhile, existing IndyCar Series teams expressed mixed reactions about the possibility of Champ Car being merged into the IRL.

At Daytona International Speedway, leading team owner Roger Penske said he supported the proposed open-wheel unification and told the St. Petersburg Times he would go so far as to provide incoming Champ Car teams with "an extra car or pieces in order to get them going." Penske switched the open-wheel portion of his racing operation from the then-CART-sanctioned Champ Car series to the IRL full-time in 2002.

However, A.J. Foyt, who has competed in the IRL since its 1996 start-up and has longstanding ties to the Indianapolis Motor Speedway and the Hulman-George family, is vehemently opposed to Champ Car teams receiving assistance from the IRL in order to make the transition between series.

"I would throw a damned fit and would want to damned near pack up my bags if that was all true," Foyt fumed during a panel discussion with former Daytona 500 winners. "And I think a lot of people that have been loyal to [the IRL] would do the same thing because it just wouldn't be right for people who had to buy and spend a lot of money."

John Oreovicz covers open-wheel racing for National Speed Sport News and ESPN.com.