A promised crackdown on pirated mobile downloads will give mobile content provider Jamster a much-needed boost in China, the company's top executive said today.

Sales of pirated mobile downloads have slowed the growth of Jamster's business in China. "We have to fight here with our competitors basically having no interest in intellectual property and just using our content and selling that," said Markus Berger-de Leon, CEO of the VeriSign subsidiary.

"We've called them, we've had our lawyers call them, and they didn't care about the infringement of our copyright."

As a result, revenue from China remains a "pretty small" percentage of the $500m (about £265m) in revenue that Jamster earned last year, Berger-de Leon said.

However, there's hope that the situation will improve. Chinese officials have promised Berger-de Leon they will crack down on sales of pirated mobile content.

"It's a special focus for them that they're going to look into this year," said Berger-de Leon, who was a member of the delegation that accompanied German Chancellor Angela Merkel on a visit to China this week. "My general sense is that things are improving."

Jamster sells downloads of mobile ringtones and animated wallpaper that it develops. The company's Crazy Frog character has been a hit in many countries, but is less popular in China. "It doesn't do as well as you'd expect," Berger-de Leon said, noting that consumer tastes are different in China.

Jamster is offering a Crazy Frog download with a World Cup theme and the song We are the champions, by Queen. That song is not well known in China and doesn't appeal to consumers in that country, Berger-de Leon said, noting that Jamster is now looking for a Chinese song to use with this download.