By Jane Macartney

BEIJING, April 18 (Reuter) - China is exacting retribution from smaller European states for backing an attempt in the U.N. to censure its human rights record, but has spared the United States to protect warming ties, diplomats said on Friday.

In Beijing's latest act of revenge, Vice Premier Zhu Rongji, China's economic tsar, called off a visit to the Netherlands and three other European nations later this month as a mark of anger at this week's failed Western attempt to censure China over human rights.

China has already postponed visits by two ministers from Denmark, the leading co-sponsor along with the United States of this week's resolution in the United Nations Human Rights Commission to criticise China for its human rights record and treatment of Tibet.

However, the United States has so far emerged unscathed from China's decision to teach a lesson to those who try to find public fault with the way Beijing handles the human rights of its 1.2 billion people.

"I don't think punishing the United States is necessarily good for China," said a specialist on U.S. affairs at China's premier think tank, the Chinese Academy of Social Sciences.

"Since (U.S. Vice President Al) Gore's visit to China, Sino-U.S. relations have improved," the specialist said. Gore came to China last month, the most senior U.S. official to visit since the bloody 1989 crackdown on student demonstrations.

"During the process of improving relations, the Chinese side is unwilling to see a deterioration in the situation," the Chinese academic said.

Casting a long shadow over Sino-U.S. relations is the prospect of a summit in Washington for President Jiang Zemin, who is said to regard the trip later this year as crowning his foreign relations policy and wants to be seen on the White House lawn with all the pomp of a state visit.

"It is not easy to improve Sino-U.S. relations," the academic acknowledged, speaking after two years of see-sawing ties that led to a virtual freeze on exchanges between Washington and Beijing amid a fierce row over Taiwan.

Western diplomats agreed that now was not the time for Beijing to launch new broadsides against the United States.

"Why aren't they retaliating? Because the U.S. is strong and powerful," said one diplomat.

"There is no way they are going to cancel any meetings with the United States because these are meetings that they want to happen," he said.

"They are not worried about these smaller countries, whether these exchanges go ahead is neither here nor there."

Vice Premier Zhu, one of seven members of China's powerful Politburo standing committee and the man in charge of China's economy, had been due to visit the Netherlands, as well as Ireland, Austria and Luxembourg in late May.

"These are small countries," said the Chinese academic when asked why Beijing had exacted retribution.

It was the first time that China had taken concrete action against nations who had supported the resolution.

Diplomats said Beijing may have chosen to escalate its response to show European nations that while it had come to expect censure from the United States, it expected a different approach from Europe.

"They seem to be saying 'We expect these stupid antics from the U.S. but not from you'," the diplomat said.

China rallied strong support from Third World countries at the United Nations Human Rights Commission in Geneva on Tuesday and sank the Western resolution.

It was the seventh year since 1990 that Western countries failed to achieve even a vote on the issue in the 53-member body despite heavy lobbying.