The logo and trading symbol for U.S. coal miner Peabody Energy Corp. are displayed on a screen on the floor of the New York Stock Exchange (NYSE) in New York, U.S., April 4, 2017. REUTERS/Brendan McDermid/ File Photo

MELBOURNE (Reuters) -Peabody Energy is set to reveal on August 19 whether it will continue with its $3.78 billion bid for Anglo American's Australian coking coal mines, as time ticks down for it to renegotiate a lower price for the deal.

The U.S. miner last year agreed to buy the mines in Queensland's Bowen Basin, the world's top coking coal region, as part of its move into becoming a coking coal producer.

But in March, the Moranbah North mine was closed due to high gas levels, leading Peabody to trigger a clause that allows a party to break or renegotiate a deal if a significant negative event occurs between signing and completion. In this case, it gave a 90 day consultation process which expired on August 3.

Since it has not reached a revised agreement with the seller, Peabody intends to provide an update on August 19, it said at its results.

"We believe a last minute deal has become less likely, and our base case now is that this goes to arbitration," Jefferies said in a note on Monday. The broker estimates a $316 million value hit if the Moranbah North mine is able to be ramped back to full capacity within three months from Sept 1.

Anglo says the event does not qualify as significant since damages and downtime are likely to be limited. CEO Duncan Wanblad has said it is confident in its legal position, is prepared to rerun a sale process and next steps were up to Peabody.

Part of the standoff is because it is unclear when the mine will be able to restart while the state regulator assesses its safety. The regulator did not provide a timeline when contacted by Reuters but said the mine was undergoing a "staged approach" to reentry as it prioritised worker safety.

For Anglo, any arbitration would push back its restructure, and may raise concerns around mine management and choice of buyer. Another process would attract strong interest from previous bidders but would push back completion of a sale into 2026, Wanblad said.

For Peabody, ending the deal would ease the pressure of looming repayments to a $2 billion dollar bridge loan due from late November. Peabody posted a second quarter loss as coal prices fell by a third from a year earlier. Peabody did not immediately comment outside office hours.

(Reporting by Melanie Burton in Melbourne; Additional reporting by Scott Murdoch in Sydney; Editing by Michael Perry)