The billionaire financier Nat Rothschild has accused the board of the miner Bumi of subjecting long-suffering shareholders to an "inferior" deal, as the scandal-scarred group desperately tries to untangle its convoluted ownership structure.
The scion of the Rothschild banking dynasty has fought a long-running battle to wrest back control of the Indonesia-focused group he co-founded with the Bakrie family in 2010.
Mr Rothschild and the Bakries fell out soon after floating Bumi on the London Stock Exchange, while hundreds of millions of dollars were found to have gone missing earlier this year and the shares have been suspended since April.
A ray of light has been that the Bakries have been in talks to sever ties with Bumi for the past nine months. This was a cash and shares proposal that would have cleared up ownership of various key assets and cancelled the Bakries' nearly one-quarter stake in Bumi.
However, yesterday Bumi confirmed details of an alternative, very differently structured proposal which it insisted was economically "consistent" with the original option.
Under the new terms, the outgoing Bumi chairman, Samin Tan, would double his shareholding in the group to nearly 48 per cent by buying out the Bakries. The two-stage deal would then see the Bakries buy back Bumi's 29.2 per cent stake in the similarly named PT Bumi business for more than $500m (£335m). This would finally unwind a complicated ownership structure that has confounded the City and infuriated investors.
Mr Rothschild, who quit Bumi's board in October but remains a major shareholder, argued that the "new proposal deprives minority investors of any upside in respect of the Bakrie stake in Bumi".
He also renewed his attack on Mr Tan, arguing that the proposal "consolidates" his control of the business. By owning nearly half of Bumi's stock, Mr Tan has to make an offer for the whole of the business under takeover rules, but this is not part of his thinking, and so would need a waiver to drop this requirement.
Mr Tan is due to step down as chairman once a successor has been identified, but Mr Rothschild believes he should leave the board immediately.
Mr Rothschild added: "The primary source of Bumi plc's difficulties over the past three years has been the concentrated control by the Bakrie concert party, which included Samin Tan. This deal does not change that."
Instead, he would like to see individual shareholders given the opportunity to first purchase parts of the Bakries' stake. Mr Tan would then be allowed to take up any stock that is not sold.
Nicholas von Schirnding, Bumi's chief executive, has been stunned by the "mess" he inherited after taking over at the start of the year. Most notably, there was a $201m black hole of unauthorised expenditure at the group's PT Berau business, which has led to a wholesale review of financial controls at the group.