Customers check P&G products at a supermarket in Shanghai.

For Procter & Gamble (P&G) there may be an even greater assault on its business than the ongoing gloomy world economy - fakes and brand infringement.

The world's largest personal-care products manufacturer has shown how seriously it takes the threat by prevailing in the latest round of a nine-year brand protection battle against a Guangdong shampoo maker.

Yet the fight could still go on for many years to come.

It all began when similar trademarks for P&G's Whisper brand - Hushubao in Chinese - and the mark Hushibao from Yaman Cosmetics Co triggered the protracted fight.

Established in 1994, Yaman Cosmetics Co in Guangzhou, capital of Guangdong province, registered the Hushibao brand with the Trademark Office of the State Administration for Industry and Commerce (SAIC).

Due to similar pronunciations - Hushibao and Hushubao - P&G China opposed Yaman's application in 2000, but in late 2001 the trademark was approved.

P&G soon took action to fight the decision and began a seven-year battle - which again ended in failure.

Two rounds of defeat did not stop P&G. This time it filed a complaint in Beijing No 1 Intermediate People's Court against both Yaman Cosmetics Co and the Trademark Appeal Board of the SAIC.

The court recently ruled to overturn the decision on the Hushibao trademark and ordered a new round of examination.

"After a nine-year tug of war the latest verdict takes the problem back to the starting point absolutely - to examine the trademark once again," said Yin Xueqian, a lawyer specialized in trademark lawsuits.

"It is the starting point for a new round of a battle in the next eight to nine years and it will cost a lot," Yin said.

"Compared to many other kinds of business competition, a lawsuit is more complicated to handle, which always calls for attaching great attention and power to such a campaign," said Yin.