The CAS upheld a British appeal against relegation after the International Equestrian Federation (FEI) tried to demote three teams instead of two last season.

Britain can now take its place in the 2010 Nations Cup when the eight-event series starts next month.

The 10-team competition is seen as important preparation for riders and horses targeting the 2012 London Olympics.

The row began last August, when Britain was, with Belgium, tied in second-to last place on the series table.

Usually the two lowest ranking teams are relegated, and this was the case with bottom-placed Italy.

However, the FEI Bureau decided on August 24 that it would allow the teams of both Britain and Belgium to compete in the 2010 FEI Nations Cup Top League.

Then, in December, the FEI reversed their decision, and said both teams were out.

But the British Equestrian Federation (BEF) appealed to the FEI Bureau.

When this was unsuccessful, the BEF appealed to the Lausanne-based CAS.

CAS said: "The CAS has allowed the appeal filed by the BEF [British Equestrian Federation] on 5 February 2010 and has annulled the decision of the FEI [International Equestrian Federation] Tribunal of 21 January 2010.

"The 15 September 2009 resolution by the FEI Bureau deciding for a relegation of the teams of Great Britain, Belgium and Italy from the FEI Nations Cup is set aside to the extent that it relegates the team of Great Britain from the 2010 edition of the FEI Nations Cup."

Belgium did not challenge the FEI decision.