Venus Williams and Ana Ivanovic will headline this summer’s WTA Tour event in Auckland, but the No.1 seed with be Italy’s Roberta Vinci.

ASB Classic organisers have previously announced that grand slam winners Williams and Ivanovic will be coming to the tournament, which runs from December 30 to January 4.

The full field released on Wednesday contains seven top-30 players, headed by Vinci, the world No.14.

During 2013, Vinci won two singles titles, made the US Open quarter-finals and reached a career-high ranking of 11.

The 30-year-old, who is also the world’s top-ranked doubles exponent, has competed in Auckland once before, reaching the second round in the last tournament.

Ivanovic is a former French Open titleholder and, with her ranking of 16, the Serbian will be the Classic’s No.2 seed.

Completing the top four seeds are Belgian Kirsten Flipkens and Romania’s Sorana Cirstea.

Williams has won seven grand slam singles titles, but the American, a former world No.1, has been battling health issues and has a present ranking of 48.

New Zealander Marina Erakovic, the world No.47, will be back again for her home event.

Also returning is 2010 champion Yanina Wickmayer of Belgium.