GENEVA, Nov 25 (Reuters) - Japan called on World Trade Organisation members on Wednesday to agree tougher rules on how far states can go to defend themselves against unfairly priced imports, warning excessive retaliation could disrupt commerce.

WTO rules allow members to impose duties on imports that are "dumped" -- or sold for less than they cost at home -- if they damage businesses in the importing country.

But such anti-dumping investigations and duties are often themselves criticised for being unfair and motivated by protectionism, and are the major cause of trade disputes.

Reform of anti-dumping rules was one of Japan's top priorities in the WTO's long-running Doha round, said Hiroyuki Ishige, vice-minister in Japan's Ministry of Economy, Trade and Industry (METI).

Japan feared that the gains to the world economy from cutting tariffs to open markets in a Doha deal could be undermined by unwarranted use of anti-dumping measures, he told a meeting of senior WTO negotiators.

"It is not a theoretical concern. It is a real concern. Dumping is sometimes found to exist when there is none," he said according to a text of his remarks made available to Reuters.

Ishige said some Japanese industries were suffering from anti-dumping measures imposed over 30 years ago -- an apparent reference to the U.S. practice of renewing these duties instead of allowing them to expire automatically after a set period.

Japan is leading a campaign at the WTO against the controversial U.S. method of calculating anti-dumping duties, known as zeroing, which has been repeatedly condemned by WTO dispute panels, but which Washington insists is fair.

Ishige, who did not comment directly on zeroing, noted in his statement that the number of new anti-dumping investigations had risen 28 percent in 2008.

Between July 2008 and June 2009, when the number of anti-dumping investigations notified to the WTO rose 15 percent from the previous 12 months to 217, Japan did not launch any probes at all, and was the target of two -- both by India, the most active user of the remedy, WTO figures show.

Ishige also presented a document to the meeting from a group of 15 countries known as the Friends of Anti-dumping Negotiations, which is coordinated by Japan, calling for faster progress on the anti-dumping talks.

The other members are Brazil, Chile, Colombia, Costa Rica, Hong Kong, China, Israel, Mexico, Norway, Singapore, South Korea, Switzerland, Taiwan, Thailand and Turkey -- all active exporters like Japan.