A trust controlled by British financier Nat Rothschild and the parent of Russia's Siberian Coal Energy Co are considering making a cash offer for coal miner Asia Resource Minerals Plc (ARMS.L), which has most of its operations in Indonesia.

The potential offer from NR Holdings and SUEK Plc comes less than a week after ARMS received notice of a possible 210 million pound ($313 million) bid from Asia Coal Ventures (ACE), a vehicle funded by Indonesia's Sinarmas Group.

ACE's potential bid risks scuppering a long-awaited restructuring of ARMS backed by Rothschild, who co-founded the company with Indonesia's prominent Bakrie family in 2010.

Bitter boardroom battles and tumbling coal prices have slashed ARMS's market value by over 90 percent since then. At Monday's close, the company was worth about 147.2 million pounds.

NR Holdings said the restructuring would give ARMS financial stability in the short and medium term. It urged investors to vote in favor of resolutions to be proposed at a shareholder meeting later this week to avoid a "likely" default of notes due this year.

"Shareholders are urged to vote in favor of the resolutions and to take no action should ACE make an offer for the company," NR Holdings said in a statement issued after the London Stock Exchange closed on Monday.

Nat Rothschild is the third-largest shareholder in ARMS, while NR Investments is the fourth-largest, according to Thomson Reuters data.