WASHINGTON (REUTERS) - Singapore has reached a tax information-sharing agreement with the United States under a new law meant to combat offshore tax dodging by Americans, a US Treasury Department spokesman said on Monday.

Set to take effect on July 1, the Foreign Account Tax Compliance Act of 2010 (FATCA) will require foreign banks, investment funds and insurers to hand over information about Americans' accounts that have more than US$50,000 (S$62,500) to the US Internal Revenue Service.

Foreign firms that do not comply face a 30 per cent withholding tax on their US investment income and could effectively be frozen out of US capital markets.

The Singapore deal, known as an intergovernmental agreement, was expected for more than a year and is significant because it broadens FATCA's dragnet to a major Asian financial centre, sources have said.

Like most of the other FATCA deals, the Singapore agreement will allow Singapore firms to report US account-holder information to their local tax authority, which will send it along to the IRS. The Singapore deal was agreed "in substance" and must be finalised by the end of the year.

Financial firms in countries that have not reached a FATCA pact must report directly to the IRS and risk violating local privacy laws.

More than 60 IGAs have been negotiated to date, including deals with Indonesia, Peru and Kuwait announced in recent days, according to the Treasury Department's website.

FATCA was enacted after a scandal involving Americans hiding money in Swiss bank accounts.