SENIOR financial regulators have hailed a co-operation pact signed between Hong Kong and the United States as 'a milestone' in clamping down on international fraud. A memorandum of understanding initialled in Washington yesterday between the Securities and Futures Commission (SFC) and the US Securities Exchange Commission (SEC) was 'as comprehensive as any the SEC has ever signed', the US regulator's chairman, Arthur Levitt, said. SFC chairman Anthony Neoh flew to the US capital to sign the agreement and a declaration of co-operation with the US Commodities and Futures Trading Commission, with which the Hong Kong authorities have a record of co-operation in fighting fraudulent investment shops. Together, the two documents formalised a process for the two financial markets to share information, request help in investigations and - most notably - subpoena potential suspects and witnesses on each other's behalf. With Hong Kong having changed its laws to allow the SFC to take regulatory action on behalf of another country, Mr Neoh said the agreement completed the picture. The US agreement follows a similar code signed between the SFC and its Chinese counterpart. The pact prompts the signatories to inform each other on possible violators. The agreements with both US agencies cover several financial services firms, including futures and foreign exchange traders, stockbrokers and investments advisers. They also provide for each party to keep confidential files, documents and share other information to investigate fraud. The agreement lists the ICAC, police, Monetary Authority and stock and futures exchanges as agencies engaged in helping their US counterparts.