(Reuters) - The U.S. Office of Financial Research, a government agency which conducts independent financial research and analysis, said on Wednesday it launched an online tool that allows investors to analyze the securities held by money market mutual funds.

The introduction of OFR's "Money Market Monitor" comes at time when regulators have tightened oversight of the $2.7 trillion industry following the collapse of the Reserve Primary Fund in September 2008 at the height of the global financial crisis when its share price fell below $1.

Money funds play a critical role in wholesale short-term financing. During the financial crisis concerns emerged about Lehman Brothers and the rest of Wall Street’s exposure to subprime mortgage debt. Investors pulled out of money market funds holding debt issued by these banks, causing the value of the funds to plummet and cutting off a key source of funding for the banks.

In October, institutional prime money funds, which can invest in riskier corporate securities in addition to government debt, will be required to use a floating share price rather than a fixed $1 per-share price as part of post-crisis reforms to the market.

"A lack of detailed data about fund holdings blocked regulators from seeing risks quickly in 2008. Since then, regulators have begun to require funds to report detailed data about their holdings more frequently," OFR deputy director for research and analysis Stacey Schreft said in a statement.

The Money Market Monitor analyzes more than 4 million records on monthly data of about 500 funds over five years based on these funds' monthly filings with the Securities and Exchange Commission.

New data will be available on the OFR money fund program after the fifth business day of each month.

The OFR, which was created by the 2010 Dodd-Frank financial reform law, is part of the U.S. Treasury Department but operates independently from the Treasury.

(Reporting by Richard Leong; Editing by Meredith Mazzilli)