(AP) - The Obama administration on Thursday unveiled a sweeping overhaul of the financial system designed to impose greater regulation on major players like hedge funds.

Treasury Secretary Timothy Geithner told lawmakers that the changes are needed to fix the flaws exposed by the current financial crisis, the worst to hit the country in seven decades.

The goal is to repair a system that has proven "too unstable and fragile," he said.

"Over the past 18 months, we have faced the most severe global financial crisis in generations," Geithner said in testimony to the House Financial Services Committee. "To address this will require comprehensive reform. Not modest repairs at the margin, but new rules of the game."