The Tangguh LNG plant, operated by oil major BP, has offered three cargoes for loading in August and September via a tender that closes on Thursday, the sources said, declining to be named as they were not authorised to speak with media.

Earlier this month, Tangguh had also offered 500,000 tonnes per annum of LNG for loading from the plant over 2022 to 2025, in a tender that closed last week, the sources said.

Separately, stated-owned Pertamina has offered two cargoes for loading from Bontang LNG export plant in June and July, one of the sources said.

Indonesia's spot cargoes have been increasing in recent months after at least one domestic buyer cancelled an order due to cheaper coal prices and as term buyers from North Asia nominate fewer cargoes due to the wide price disparity between term and spot cargoes, trade sources said.

A Pertamina spokeswoman declined to comment on the tender while BP could not immediately be reached.

LNG inventories are building as Pertamina's buyers had asked for changes to shipping schedules in May, which is expected to result in unmanageable gas stocks at Bontang plant in late May, Wisnu Prabawa Taher, spokesman for upstream oil and gas regulator SKK Migas, said in a press release earlier this week.

He said that SKK Migas has been coordinating with Pertamina and Badak NGL, operator of the Bontang plant, and has urged Pertamina to take gas from Muara Bakau gas block on schedule, make technical preparations to anticipate high inventory, and prevent a disruption in gas supply from the Muara Bakau block.

The Bontang LNG plant gets the bulk of its gas from the Mahakam block but also receives some from the Muara Bakau block.

The Pertamina spokeswoman said the company will coordinate with relevant stakeholders on the high inventory at Bontang.

Indonesia has exported 35.9 standard cargoes of LNG from Bontang and Tangguh plants for January-April 2019, with

Bontang LNG shipping 18.2 cargoes of LNG, and Tangguh shipping 17.7 cargoes, SKK Migas said earlier this month.

There are 11 uncommitted cargoes of LNG from Bontang after state electricity utility Perusahaan Listrik Negara (PLN) cancelled an order, SKK Migas official Arief Setiawan Handoko had said late last week.

(Reporting by Jessica Jaganathan in SINGAPORE and Wilda Asmarini in JAKARTA; Editing by Tom Hogue)

By Jessica Jaganathan