* Top EU court says 'Bud' trademark ruling must be reviewed
* Lower court had ruled against AB InBev
* Top court ruled against AB InBev over 'Budweiser' in 2010
(Adds AB InBev comment)
BRUSSELS, March 29 (Reuters) - A European Union court must review its decision to ban Anheuser-Busch InBev from using the "Bud" trademark in the European Union after mistakes in the ruling, the EU's top court ruled on Tuesday.
The European Court of Justice referred the case back to the General Court -- the second highest in the European Union -- arguing that the latter made three errors of law in its December 2008 ruling.
AB InBev has been in a long-running dispute with Czech brewer Budejovicky Budvar over the rights to the trademark names "Budweiser" and "Bud" -- a David versus Goliath litigation that has run on and off for a century.
Budvar had argued that its 'Bud' was a protected brand in Austria, France, Italy and Portgal, preventing AB InBev from registering the trademark throughout the European Union.
The top court on Tuesday said this was only the case if a sign or trademark was actually used significantly in the course of trade, something the lower court had not taken into account.
AB InBev, which owns the rights to Budweiser or Bud trademarks in 23 of the 27 EU states and launched Bud in Russia last year, said it welcomed Tuesday's verdict.
"As a result of the ruling, we are confident that we will obtain an EU-wide registration for Bud," the company said in an emailed response.
Last July, the European court ruled that AB InBev could not register "Budweiser" as a trademark in the bloc.
AB InBev has said the July ruling would have no effect on its business.
(Reporting by Robert-Jan Bartunek and Philip Blenkinsop; Editing by Rex Merrifield and David Holmes)