The 30th edition of the ARAG ATP World Team Championship, to be held from May 20-26 at the Düsseldorf Rochusclub, will feature all of its four-time champions: Spain, the USA and Germany.

Spain enters as the second-ranked tennis nation in the elite eight-team field, behind the Czech Republic. David Ferrer, who broke into the Top 10 for the first time in 2006 and finished the year ranked No. 14, and recent Valencia titlist Nicolas Almagro will attempt to lead their country to its first ARAG ATP World Team Championship title since 1997.

The USA, who joins host Germany as the only countries to have participated in the tournament every year since its inception in 1978, will be led by James Blake and the No. 1 doubles tandem of Bob and Mike Bryan. The 27-year-old Blake captured five titles in 2006 to finish a career-high No. 4 in the ATP Rankings, while the Bryans combined for seven doubles titles and completed the career Grand Slam with the Wimbledon crown. Mardy Fish, the 2006 ATP Comeback Player of the Year, will join his compatriots in his Düsseldorf debut.

Tommy Haas and Nicolas Kiefer will each represent the German contingent for the seventh time. Both were members of the 1998 championship team in their first event appearance, a squad which also included tennis legend Boris Becker, and recaptured the title again in 2005. Kiefer was also a member of last year's runner-up team. Haas finished No. 11 in the ATP Rankings last season and won three ATP titles, but Kiefer has been sidelined since Roland Garros due to a severe wrist injury.

The Czech Republic tops the 2007 leader board of nations, based on the combined year-end 2006 ATP Rankings of its two best players: No. 13 Tomas Berdych and No. 19 Radek Stepanek. The Czech Republic was a finalist at the World Team Championship three times, most recently in 2003, a 2-1 defeat to Chile. Stepanek notched the only victory in the final by defeating Marcelo Rios in straight sets.

Other teams in the confirmed 2007 field include Argentina (Jose Acasuso, Agustin Calleri, Guillermo Canas), Belgium (Kristof Vliegen, Olivier Rochus, Xavier Malisse) and Sweden (Robin Soderling, Jonas Bjorkman, Thomas Johansson). A wild card team will fill the eighth berth.

The ARAG ATP World Team Championships, which has been contested at the Rochusclub in Düsseldorf since 1978, features the world's eight best tennis nations. With a squad of three to five players, the eight nations are drawn into two groups of four teams. Evnery country plays a minimum of three ties, consisting of two singles and one doubles rubber, against all three of the other nations in its group. The leading nation of each group then contests the championship.