Williams, an eight-time Grand Slam champion, will be making her first appearance in the tournament.

Williams, ranked No. 8 in the world, struggled with injuries in 2006 before entering the Australian Open as an unseeded player and walking away with the win.

She also reached the quarterfinals of the French Open and Wimbledon, climbing back into the top 10 of the WTA Tour world rankings.

"I am ready to get back onto the courts and hope to return to the form I had earlier this year," she said. "My sister always loved New Haven and was incredibly successful there, and I hope to have the same kind of results."

Williams joins fourth-ranked Svetlana Kuznetsova; No. 10 Daniela Hantuchova; No. 11 and Wimbledon finalist Marion Bartoli; No. 13 Elena Dementieva; and three-time Grand Slam champion Lindsay Davenport as women's players committed to the tournament.

"Serena is truly a household name around the world, and we are thrilled to add her to the Pilot Pen field in New Haven," tournament director Anne Worcester said. "The Pilot Pen fans always adored Venus, and I am certain they will have the same kind of warm and welcoming support for Serena."

Ninth-ranked James Blake, a Connecticut native, will be headlining the men's side along with defending champion and fifth-ranked Nikolay Davydenko; No. 7 Tommy Robredo; and No. 14 Andy Murray.