You probably think that your bank keeps mum about your financial affairs. Think again. It may be selling you down the river, in order to earn some extra money.

Many banks sell your confidential account information to telemarketing firms. Salespeople then call you, flogging discount dental plans, travel clubs and other products.

Monthly payments are deducted automatically from your bank account or charged to your credit card. The bank earns commissions on the sales.

Comptroller of the Currency John D. Hawke Jr. calls some of these practices “seamy, if not downright unfair and deceptive.” You can try to get off the sales list (see below), but might not be able to.

When the telephone salespeople call you, what might they know?

Plenty.

Besides your name, age, address and phone number, the bank might have disclosed your bank account number, Social Security number, current checking account balance, credit limit, credit score (showing how creditworthy you are), the number and type of credit cards you carry and what you owe on your credit card accounts.

A case recently brought by Minnesota Attorney General Mike Hatch against Minneapolis-based U.S. Bancorp charged that some customers had their bank accounts and credit cards debited, even though they didn’t want the service.

U.S. Bancorp, which has 1,023 affiliated banks and branches, settled the case with no admission of wrongdoing. But it agreed to fines, restitution and charitable contributions of about $3 million the approximate amount it had earned on sales commissions.

Theoretically, the Fair Credit Reporting Act limits the way some of your financial records can be used.

FCRA covers credit information for example, your income, assets and employment history. Under the law, banks have to tell you that they might disclose this information, and give you a chance to take your name off the telemarketing lists. This is called “opting out.”

Unfortunately, there’s no effective way of enforcing FCRA, says Hawke, whose office regulates 2,400 national banks. The regulators don’t know what the banks are doing, and few customers know they can opt out.

What’s more, no federal law protects what’s called “transaction and experience” information namely, the details of your bank and credit card accounts. They can be disclosed to telemarketers at will, says Amy Friend, assistant chief counsel at the Office of the Comptroller of the Currency. So can your Social Security number.

U.S. Bancorp had a deal with a telemarketer called MemberWorks in Stamford, Conn., which, says Hatch, has worked with 17 of the 25 largest banks. Hatch sued MemberWorks last week, charging deceptive practices. The company denies the charge.

As part of its settlement, U.S. Bancorp agreed to stop working with outside telemarketers selling non-financial products. Wells Fargo and Bank of America announced that they would do the same.

But they can still disclose your confidential account information to telemarketers selling financial products for example, insurance and securities.

Chase Manhattan says it’s revising its telemarketing policy. Bank One says it gives telemarketers only name, address and phone number.

A financial-restructuring bill in Congress would give you opt-out rights when banks sell your account information to third-party marketers who are peddling non-financial products, such as dental plans.

But industry lobbyists and the congressional leadership defeated attempts to give you even better protection. You’ll still have no privacy rights, if your bank wants to give your confidential information to affiliated telemarketers or peddlers of financial products. If you don’t want your account information disclosed to telemarketers, here’s what to try:

(1) Call your bank and get the name of the person in charge of customer relations. Write a letter, saying that you want to exercise your legal right, under FCRA, to keep your credit information from being disclosed.

Also say that you don’t want your bank and credit-card account data disclosed to anyone selling financial or non-financial products, including the bank’s own affiliates. Some banks might agree, although they don’t have to. Ask the bank to acknowledge your letter.

(2) Write to the president of the bank, saying that you’re shocked to learn that your bank and credit-card account information can be disclosed. The more top officials hear this, the better. Ask specifically whether the bank shares your account information with affiliated or nonaffiliated companies.

(3) Tell your senator and representative that you want an enforceable opt-out right for all telemarketers, including those affiliated with financial institutions. Unless Congress hears from the public, the industry’s dollars will rule.

Rethinking annuities

Memo to people saving for retirement: If you’re looking at tax-deferred variable annuities, look twice. The industry is pumping them out to investors who want tax-sheltered gains. But there’s a lot of deceptive or inappropriate selling going on.

Variable annuities often make sense for younger people in higher tax brackets. They’re questionable for retirees, people in low brackets and workers who are investing in retirement plans such as IRAs. Yet these are the very people who are buying the most.

To understand the risks, you have only to read between the lines of a cautionary notice, released in May by the National Association of Securities Dealers.

The NASD wields authority over the people who sell VAs. The notice warned stockbrokers and insurers to disclose all the facts about these investments, including their limitations and fees.

Before you jump, here are some of the things that the NASD wants you to know:

(1) You shouldn’t buy a VA unless you’ll hold it, untouched, for many years. There’s generally a 10 percent IRS penalty for withdrawals before age 59-1/2. Most insurers impose their own penalty for withdrawals during the first six to 10 years. Some exceptions: the low-cost annuities sold by Vanguard, T. Rowe Price and TIAA-CREF.

(2) If you want tax deferral and you’re investing with money in your IRA or another retirement plan, you don’t need a variable annuity. Sure, VAs are tax-deferred, but your retirement plan is tax deferred already. Why pay for this advantage twice? You can buy regular mutual funds, at lower cost, and still enjoy tax-deferred returns.

(3) VAs are hard to justify for older people who are investing with taxable income. Money withdrawn from an annuity is taxed in your regular bracket. If you had put that same money in mutual funds outside an annuity, your earnings would be taxed at the low rate applied to capital gains.

Syndicated columnist Jane Bryant Quinn can be reached in care of the Washington Post Writers Group, 1150 15th St., Washington D.C. 20071-9200.