DUBAI- Abraaj, the Middle East's biggest private equity firm, has filed a petition in the Cayman Islands, asking the court to appoint PwC as provisional liquidators for the embattled company. "The appointment of provisional liquidators imposes a moratorium on the enforcement of all unsecured claims against the company, allowing time for a proposal to be put to creditors for the orderly restructuring of the company," it said in a statement.

The move is to thwart separate legal action by the Kuwait Public Institution for Social Security (PIFSS) and another creditor, who are seeking the liquidation and winding up of Abraaj for non-payment of debt.

Dubai-based Abraaj has been trying to stem the fallout from a row with four of its investors, including the Bill & Melinda Gates Foundation and International Finance Corp (IFC), over how it used their money in a $1 billion healthcare fund.

Abraaj has denied it misused the funds.

Abraaj's founder Arif Naqvi founded Abraaj with $60 million in 2002 and built it into an emerging market champion with assets of $13.6 billion at its peak before the row forced the firm to suspend a new fund and shakeup its management.

A court-appointed provisional liquidator helps safeguard the assets of the company until a wind-up application is heard by the court.

Naqvi said in a statement this process marks the culmination of an extremely complex and challenging phase of negotiations and detailed planning.

"Since our differences with certain investors first came to light, we have worked exhaustively and transparently to investigate the matter and address their concerns, all the while ensuring our tremendous investment teams around the world continue to support the growth of our partner companies," he said.

Abraaj, with debts estimated at over $1 billion, met its creditors earlier this month to reach a standstill deal, which the firm said was backed by the vast majority of its lenders, to facilitate the sale of its investment management business to Cerberus.

However the Kuwaiti fund, an unsecured creditor, refused to join secured creditors in the proposed debt freeze agreement. In another legal challenge to Abraaj, a little known creditor of Abraaj also started legal proceedings in the Cayman Islands seeking the restructuring of the private equity firm's liabilities.  Allen & Overy LLP, Carey Olsen and Milbank, Tweed, Hadley & McCloy LLP are serving as legal advisors and Houlihan Lokey are serving as financial advisors to Abraaj 333Holdings.

(Reporting by Saeed Azhar Editing by Alexandra Hudson) ((; +971 44536787; Reuters Messaging: