The U.S. government is prepared to provide more than $7.76 trillion on behalf of American taxpayers after guaranteeing $306 billion of Citigroup Inc. debt yesterday. The pledges, amounting to half the value of everything produced in the nation last year, are intended to rescue the financial system after the credit markets seized up 15 months ago.

The unprecedented pledge of funds includes $3.18 trillion already tapped by financial institutions in the biggest response to an economic emergency since the New Deal of the 1930s, according to data compiled by Bloomberg. The commitment dwarfs the plan approved by lawmakers, the Treasury Department’s $700 billion Troubled Asset Relief Program. Federal Reserve lending last week was 1,900 times the weekly average for the three years before the crisis.

When Congress approved the TARP on Oct. 3, Fed Chairman Ben S. Bernanke and Treasury Secretary Henry Paulson acknowledged the need for transparency and oversight. Now, as regulators commit far more money while refusing to disclose loan recipients or reveal the collateral they are taking in return, some Congress members are calling for the Fed to be reined in.

Most of the federal guarantees reduce interest rates on loans to banks and securities firms, which would create a subsidy of at least $6.6 billion annually for the financial industry, according to data compiled by Bloomberg comparing rates charged by the Fed against market interest currently paid by banks.

Not included in the calculation of pledged funds is an FDIC proposal to prevent foreclosures by guaranteeing modifications on $444 billion in mortgages at an expected cost of $24.4 billion to be paid from the TARP, according to FDIC spokesman David Barr. The Treasury Department hasn’t approved the program.