NEW YORK (Bloomberg) ? Sphinx Managed Fund, which has been embroiled in litigation because of its ties to bankrupt Refco Inc., filed its own bankruptcy petition in New York today to protect its US assets while it liquidates overseas.

Sphinx is liquidating in a Cayman Islands bankruptcy court. The petition filed in US Bankruptcy Court in New York yesterday bars creditors from trying to seize its US-based assets during the liquidation. Most of the fund's $100 million-plus in assets are in the US, according to court documents.

Sphinx "has commenced this case to ensure that the debtor's assets are not improperly attached or withheld by creditors or third parties", Kenneth Krys, the company's court-appointed liquidator in the Cayman Islands, said in court papers.

Refco creditors sued Sphinx in December to recover $312 million they said Sphinx wrongfully withdrew days before the trader's collapse while other customers were barred from doing so. As a result of the lawsuit, a US judge limited Sphinx's ability to trade. Sphinx in April agreed to pay the Refco creditors $263 million to settle the suit.

Sphinx invested $325 million with Refco unit Refco Capital Markets before the October 17 Refco bankruptcy filing, according to court documents.

On October 11, the day after former Refco chief executive Phillip Bennett announced that he had concealed $430 million in debt, the fund's investment adviser PlusFunds Group Inc. demanded Refco transfer the money, according to the complaint.

The funds were transferred on October 12. Refco the next day imposed a moratorium on additional customer withdrawals.

A group of Refco creditors has appealed court approval of the settlement, and Krys said he is investigating the accord, which was reached before he was appointed by the Cayman Islands court.

Sphinx in June sued former PlusFunds directors Christopher Sugrue, Mark Kavanagh and Brian Owens for breach of fiduciary duty. PlusFunds filed for bankruptcy in New York in March and is liquidating its assets.

Sphinx also sued former Refco CEO Bennett and Austria's Bawag PSK for aiding and abetting a fraud.