WASHINGTON, Jan 20 (Reuters) - U.S. securities regulators have laid out three possible ways to enhance oversight of investment advisers, saying they don't have the resources to conduct effective examinations.

The Securities and Exchange Commission made the recommendations in a report to Congress late on Wednesday. The report was required under the Dodd-Frank financial law.

Unlike brokers, investment advisers that manage large amounts of assets are only subject to SEC oversight and don't have a self-regulatory group.

But of the failure of the SEC to detect Bernard Madoff's Ponzi scheme reignited a debate in recent years over whether Congress should take steps to subject investment advisers to more rigorous and frequent examinations.

The SEC's study said Congress can consider imposing user fees on the industry to help the agency enhance its oversight.

Alternatively, Congress can designate a self-regulatory group for advisers or it also could authorize the Financial Industry Regulatory Authority to examine advisers who also are registered broker-dealers.

FINRA is the self-regulatory group for brokers and it has advocated for a self-regulatory regime for advisers.

The investment adviser industry, however, has generally opposed a move toward self-regulation, saying they prefer SEC oversight. Advisers have been particularly opposed to oversight by FINRA.

The SEC has struggled over the years to keep pace with the growth in the investment adviser industry, especially as the agency has grappled with a decline in staffing.

According to the study, the SEC's number of examinations for registered advisers between 2004 and 2010 decreased by 29.8 percent, from 1,543 examinations in 2004 to 1,083 examinations in 2010.

The Dodd-Frank law is expected to alleviate some of the burden on the SEC in the near-term because it shifts additional responsibility for some of the examinations to state regulators.

However, the SEC said it expected the decrease to be short-lived thanks to other provisions in the Dodd-Frank law requiring advisers to many hedge funds and private equity funds to register with federal regulators.

The SEC has asked Congress for a large increase in its budget to help it implement its new authorities under Dodd-Frank.

But Congress has remained at an impasse on budget talks, and the newly-controlled Republican House may seek to withhold additional funding amid concerns about key provisions in the Dodd-Frank law.

One way to get around the Congressional appropriations process is by imposing user fees on the industry to help fund more SEC examinations, the study said.

The study also suggested that user-fees may be a less expensive option than establishing a new self-regulatory organization, although it acknowledges that "staff has not evaluated the potential start-up or operational costs of an SRO."

The report doesn't explicitly take a view on which option is best, but SEC Commissioner Elisse Walter issued a lengthy statement saying she felt the report lacked balance and failed to address many of the benefits of self-regulation.

(Reporting by Sarah N. Lynch)