* Decision in October on whether to restrict exports - minister

* East coast shortfall could equal 10% of demand - watchdog

* Supply gap equivalent to 14 LNG spot cargoes

* Government extends gas export control trigger to 2030

* Gas producers say ample gas available to fill shortfall (Adds market context in paragraphs 5 and 9.)

By Sonali Paul and Renju Jose

MELBOURNE, Aug 1 (Reuters) - Australia said on Monday it will decide whether to curb exports of liquefied natural gas (LNG) after a watchdog urged restrictions, warning one of the world's biggest suppliers of the fuel could face a shortfall and soaring prices next year.

The government's move, after a recommendation from the Australian Competition and Consumer Commission (ACCC), comes even as the country vies with Qatar and the United States as the world's top LNG exporter.

The ACCC warned extra gas is needed to offset declining output at offshore fields that have long supplied the populous east coast, home to nearly 90% of Australia's population.

Resources Minister Madeleine King said she would consult with LNG exporters and Australia's trading partners before making a decision in October.

The ruling could affect fuel supplies and prices in 2023 for global consumers already roiled by gas disruptions due to the war in Ukraine. The shortage is small in global terms, but a call to divert precious cargoes away from the export market will add to concerns about a growing tightness in energy supplies.

Export curbs would most likely impact the Gladstone LNG joint venture led by Santos Ltd, whose partners are TotalEnergies SA, Korea Gas Corp (KOGAS) and Malaysia's Petronas.

The call for action came in an ACCC recommendation that the government pull the trigger on the Australian Domestic Gas Supply Mechanism. The measure set up in 2017 can be used to force the east coast's LNG exporters to divert gas to the domestic market to avert shortfalls.

"Our latest gas report finds that the outlook for the east coast gas market has significantly worsened," ACCC Chair Gina Cass-Gottlieb said in a statement.

The commission found that LNG exporters are likely to withdraw more gas from the domestic market than they plan to supply. A shortage of 56 petajoules is now expected, equivalent to around 10% of demand, or 14 LNG cargoes in total. Australia has been exporting an average of 100 cargoes a month so far this year, Refinitiv Eikon data shows.

Not only did the commission warn of a shortfall in 2023 but also said it was "strongly encouraging LNG exporters to immediately increase their supply into the (Australian) market".