An 18-nation World Cup of Tennis Finals is planned as the International Tennis Federation (ITF) revamps the Davis Cup.

The week-long event, which would be held in November, has been unanimously endorsed by the ITF’s board of directors and could start in 2019.

The ITF has outlined a 25-year, $3bn (£2.15bn) plan with an investment group founded by footballer Gerard Pique.

A two-thirds majority at the ITF annual general meeting will be required for final approval of the proposals.

That meeting is scheduled to take place in Orlando in August.

“Our vision is to create a major season-ending finale that will be a festival of tennis and entertainment, featuring the world’s greatest players representing their nations to decide the Davis Cup champions,” said ITF chairman David Haggerty.

“This new partnership will not only create a true World Cup of Tennis, but will also unlock record levels of new investment for future generations of tennis players and fans around the world.”

Barcelona and Spain defender Pique said his Kosmos investment group was “thrilled to join in this exciting partnership with the ITF”.

He added: “Together we can elevate the Davis Cup to new heights by putting on a must-see World Cup of Tennis Finals featuring the top nations and top players.”

The event would be run on a round-robin format before a knockout phase, with matches consisting of two singles and one doubles rubber. Matches will be played over the best-of-three sets.

The 16 World Group nations will automatically qualify for the finals, with a further two nations to be selected.

France are the Davis Cup champions, having beaten Belgium in November.