(IDEX Online) - Troubled Petra Diamonds has agreed a debt-for-equity restructuring deal with lenders, after failing to attract any buyers.The UK-listed miner, founded by Adonis Pouroulis in 1997, was facing $650m of debts in senior secured bonds and launched a formal sales process in June to sell the company either as a whole.Today Petra Diamonds Limited (PDL) announced a deal whereby debtholders will acquire 91 per cent pf the company, in exchange for reducing its debt to $337m in new notes, and contributing $30m to provide it with much-needed liquidity. The so-called lock-up agreement with South African lenders and the noteholder group is due to be signed in early November, subject to shareholder approval.Petra's chief executive Richard Duffy said: "We are very pleased to announce today an agreement in principle between the Company and our financial stakeholders on the key terms of a restructuring that puts PDL on a viable footing going forward, for the benefit of all our stakeholders.Petra bought the famous Cullinan mine, in South Africa, and other deposits deemed unprofitable by De Beers, including the Finsch and Koffiefontein mines, also in South Africa, and the Williamson deposit in Tanzania.Its famous Cullinan mine was the source of the largest rough gem-quality diamond ever - the 3,106.75-carat Cullinan Diamond that became part of the British Crown Jewels. Pic courtesy Petra Diamonds Limited