Bumi, the coal company at the centre of dispute between co-founders Nathaniel Rothschild and Indonesia's Bakrie family, said it hasn't uncovered a "black hole" in a probe of contractors at its largest unit.

"We've not discovered any black hole or any significant issue that we are concerned about, and we've completed quite a lot of work," chief executive Nick Von Schirnding said yesterday, referring to an investigation at its PT Berau Coal Energy.

The review has forced Bumi to delay releasing 2012 earnings. “We are doing extensive forensic work into potential undisclosed liabilities, and that is more difficult.” Bumi shares plunged 69 per cent last year in London amid an investigation that started in September into “alleged financial irregularities.”

At the same time, Bumi is working to separate from its other Indonesian coal affiliate PT Bumi Resources, controlled by the Bakries, in a deal valued at more than $580 million at the time it was announced.

That transaction remains on schedule for June completion, Von Schirnding said. “I’m determined to emerge from this with a clean set of numbers and assets that everybody can have full confidence in,” he said from London where the company yesterday requested a halt in trading of its stock.

“It is very frustrating, I am very angry that we have to suspend these shares temporarily.” Bumi gained 7.8 per cent to close at 259.3 pence on April 19th.

The stock has declined 5.6 per cent this year, giving the company a market value of 625 million pounds ($952 million). The coal producer said on April 12th it had been unable to verify some spending at Jakarta-based Berau.

Four days later Bumi chief financial officer Scott Merrillees said he would resign in June. Berau’s management team is overseeing a full audit review and is verifying contracts signed by the Indonesian company, Bumi said yesterday. ( Bloomberg )