* Nike made "few hundred million dollars" from soccer shirts
* Big potential in United States, China
* Nike not interested in stake in soccer club
BERLIN, July 8 (Reuters) - U.S. sportswear maker Nike Inc , battling Adidas AG to be the world's biggest soccer brand, expects kit sales to keep growing fast after the World Cup, its chief executive was quoted as saying in a German newspaper.
Nike last month reported soccer-related revenue rose 21 percent, excluding currency fluctuations, to $2.3 billion in the financial year ended May 31.
"I promise you it will continue like that in the next year," CEO Mark Parker told the Handelsblatt daily, in an interview due for publication on Wednesday, adding that the $2.3 billion did not include "a few hundred million dollars" from shirts.
"The United States offers huge potential in particular, enthusiasm for football is there in any case. And in China there are tremendous growth opportunities," Parker added.
Nike and Adidas are battling for supremacy in the soccer kit industry, with the American company having made big inroads into a sport that its German rival long dominated despite the fact Adidas has been a World Cup sponsor since 1970.
Adidas, which is providing kit to semi-finalists Germany and Argentina, is aiming for record soccer sales of 2 billion euros ($2.7 billion) this year. Nike is supplying the other two semi-finalists - hosts Brazil and the Netherlands.
Parker added that Nike is not interested in taking a stake in a soccer club, like Adidas' holding in Bayern Munich or rival German firm Puma's reported talks with Borussia Dortmund. "We stick to our core business," he said.
A source with knowledge of the matter said Nike would not renew a long-running kit supply deal with English soccer club Manchester United because of the cost of a new contract, clearing the way for a lucrative new deal with Adidas.
($1 = 0.7331 Euros) (Reporting by Emma Thomasson and Joern Poltz; Editing by David Holmes)