Here are some tips from the U.S. Securities and Exchange Commission for avoiding boiler room schemes:

Are the broker and firm licensed? If the brokerage is based outside the United States, check with regulators in its home country. The International Organization of Securities Commissions has links for many regulatory bodies at its Web site, www.iosco.org.

If the broker claims to work for a U.S. firm, call the National Association of Securities Dealers' hot line, 1-800-289-9999, or visit its Web site, www.nasd.org, which has a searchable directory of registered firms.

Is the stock registered? Visit the SEC Web site, www.sec.gov, and search its EDGAR database.

The SEC notes, however, that even if a company has registered its securities and filed all the required reports, there's no guarantee that it's a good investment. Similarly, opportunities that are not registered with the SEC are not necessarily frauds or even bad investments.

Where does the stock trade? Many fraud schemes involve "microcap" companies, whose limited assets or low share prices do not meet the minimum standards for the New York Stock Exchange, American Stock Exchange or Nasdaq. The stock is relegated to the lesser markets, where trading volumes are often low and prices can be volatile.

What is the stock price in the United States? Before buying shares from an overseas broker, check the trading price on the U.S. exchange where it's listed. Dishonest brokers may mark up the price.

The www.nasdaq.com Web site provides quotes for stocks listed on the New York Stock Exchange, American Stock Exchange, Nasdaq and Over-the-Counter markets.

Is there independent research on the company? The SEC says investors always should request and read information about the company, including a prospectus and recent financial statement. Then they should investigate the company on their own. The Internet can be a powerful tool.

The SEC has three more suggestions for investors who are approached by unfamiliar companies.

First, look past the name. Boiler room brokers sometimes appropriate the names of legitimate people and firms. Investors should compare any address a broker provides with the address on file with their securities regulator or the NASD. A discrepancy could be a sign of fraud.

Next, investors should do their own research on the Internet or through printed stock guides available through libraries. The clients or official-sounding organizations provided as references by the broker could be part of the scheme.

Finally, investors should be wary of unusual banking instructions. Reputable U.S. brokers generally have their accounts at U.S. banks. They would not ask an investor to transfer money to a foreign bank or send it to the United States for further credit to a non-U.S. bank.