(Adds comment, details)
TOKYO, June 28 (Reuters) - Japan's anti-monopoly regulator said on Wednesday that all new contracts for liquefied natural gas (LNG) must not contain restrictions on the resale of cargoes of the fuel, ending a practice the country's buyers say is unfair.
The ruling is likely to result in more trading of LNG cargoes by buyers in Japan, the world's biggest importer of the fuel, and could lead to a challenge to similar restrictions elsewhere in Asia.
Asian LNG buyers have long complained that the long-established practice of placing destination clauses in LNG contracts unfairly restricts trading of the fuel when it would make more economic sense to on-sell supplies into other markets.
The ruling comes as many producers have already relented on the issue, offering contracts without resale or destination restrictions.
"They had been talking about this for quite a while. A lot of the sellers already loosened their restrictions. It will probably impact the Qatari contracts especially in this oversupply climate," a Singapore-based LNG trader said.
Producers in Qatar have several long-term LNG contracts up for negotiation with Japan between now and 2021, while producers in Malaysia will also be affected.
The move is a reprise of the upheaval in Europe in the early 2000s when the European Union found certain gas market practices anti-competitive.
Japan's Fair Trade Commission late last year ordered the country's LNG buyers to provide details on contract requirements that prevent them from reselling the liquefied fuel to third parties.
Japan's trade ministry issued a report in May 2016 recommending that destination clauses be abolished or relaxed in the future so that utilities can resell cargoes or take advantage of arbitrage trade opportunities.
(Reporting by Osamu Tsukimori; Writing by Aaron Sheldrick; Editing by Richard Pullin)