WASHINGTON — For years, hedge funds barely registered on the Washington agenda, and that was just the way their managers liked it.

These investment pools designed for wealthy individuals flourished in the shadows: They collected more than $1 trillion; seized control of underperforming companies; and increasingly drew money from gigantic pension funds, including those of government employees.

But now they are so large and numerous — there could be as many as 9,000 hedge funds — that federal regulators, state authorities and lawmakers are clamoring to learn more about them, including whether fraud and risky trading flourish in their secretive operations.

This week, the Securities and Exchange Commission staff confirmed that it is conducting a sweeping inquiry into whether hedge funds are misusing information they receive from investment banks to get a jump on trades and sweeten their profits. Last week, federal prosecutors in New York charged a fund manager with criminal securities fraud that it said cost investors $88 million.

And German officials put hedge fund risks at the top of the agenda of the Group of Seven meeting that concludes today in Essen, Germany.

"All over the place, there are signals of rising regulatory concern," said Damon Silvers, who tracks the issue at the AFL-CIO. "It's certainly not an issue that's going away. If anything, it's escalating."

The last time a major coalition of federal agencies said anything on the subject was in 1999, after star-studded hedge fund Long-Term Capital Management nearly collapsed and shook the financial markets. Back then, the agencies rejected direct regulation of the funds, a position the U.S. government still holds.

Federal scrutiny, if not action, has increased significantly, however. High-ranking Treasury Department officials held 15 meetings over three days last year with representatives from prominent hedge funds, investors, lawyers and others to gather information about hedge funds' operations. Next week, the President's Working Group on Financial Markets — including officials from the Treasury, Federal Reserve Board, SEC and Commodity Futures Trading Commission — will meet and consider issuing a statement to highlight the importance of the funds to the market and the risks, insiders say.

For now, federal officials say the best way to police hedge funds is to ensure that banks, which handle billions of dollars of the funds' business in loans and trades, are aware of the risks they face. Market analysts add that it is unlikely that the collapse of one large hedge fund would topple the market. But under certain scenarios, an over-leveraged fund could set off a string of events that could bring a large investment bank to its knees, touching off a dangerous chain reaction.

Key lawmakers, including Sens. Charles Grassley, R-Iowa, and Arlen Specter, R-Pa., and House Financial Services Committee chairman Barney Frank, D-Mass., have expressed interest in learning more about how the industry operates, including holding hearings. But lawmakers have mostly stopped short of calling for stiff oversight of the funds, in part out of fear that it might do more harm than good. In addition, many lawmakers have said that if rich people want to put their money at risk, there is no public policy reason to get in their way.

The SEC has the authority to bring civil fraud cases against funds and their managers. Since June 1999, the agency has filed more than 100 such cases, according to public records.