Sanrio, the Japanese maker of the children's character Hello Kitty, has vowed to fight a court ruling that its rabbit character Cathy, right, is "too similar" to Miffy, the popular Dutch rabbit, above.

A court in Amsterdam ruled Sanrio's Cathy, depicted as a friend of the popular cat Hello Kitty, infringes the copyright for Miffy, the well known Dutch character created by Dick Bruna, top. Miffy, known as Nijntje in Dutch, has an "x" for a mouth and has inspired several animated television series in Japan.

The ruling ordered Sanrio to immediately stop making, selling and marketing Cathy goods in the Netherlands, Belgium and Luxembourg, and ordered the company to pay €25,000 (£21,800) a day in the event of non-compliance, up to €2m.

"We object to this ruling and do not believe any copyright infringement took place, a view we intend to express legally," Sanrio said today. "At this point, we believe any impact on company earnings will be limited."

Bruna created Miffy in 1955 and translated versions of his books soon became popular in Japan.

Cathy has been marketed since 1976 as one of the friends of Hello Kitty, who made her debut in 1974. Both have appeared in an animated series with spin-off clothing and merchandise popular with pre-school children.

The case was brought by Mercis Media, Bruna's copyright management firm.