In the past three years, the percentage of checking accounts offered by banks nationwide that are considered free — with no minimum balance or monthly fee — has doubled, according to Bankrate.com, a research service in North Palm Beach, Fla.

"You don't have to look too far to find an institution that has a free checking account in their lineup," said Greg McBride, financial analyst at Bankrate. "These free checking accounts have long been the hallmark of your smaller, local community banks. Now you're beginning to see some of the larger players, some of the bigger national banks, rolling out their offerings as well."

A free checking account "may or may not make sense depending on who you are and your level of activity," said Les Dinkin, managing principal at NBW Consulting Group Inc. in Westport, Conn.

Free checking accounts were a staple at many banks and thrifts 20 years ago but began to disappear as banks moved to flat fees, a more stable source of revenue than interest income that varies with rates.

In an effort to encourage consumers to do more business, banks allowed people to avoid the monthly fees and other charges by maintaining a certain balance in the account — sometimes as much as several thousand dollars — or by linking the account to other products and services. That practice alienated consumers who can't or won't keep that much money in the bank.

But as banks' fee-based businesses struggled while their consumer businesses boomed, companies brought back free checking — or introduced accounts requiring a low balance of, say, $100 — in a bid to gather more deposits.

"The checking account remains the centerpiece of a consumer's banking relationship," McBride said. "By offering free checking, institutions are opening the door to potential customers that they ultimately hope to cross-sell into other products and services."

Three years ago, 6 percent of all checking accounts offered by banks in the 35 largest markets were considered free, according to Bankrate.com. Today, that has nearly doubled to 11 percent.

However, that figure doesn't include free accounts with other restrictions, such as requiring the customer to sign up for direct deposit, so there may be other options that basically are free that fit a consumer's needs.

"It means that an existing account that you have or an existing institution that you're already banking with might offer an account that could be free if you're willing to sign up for direct deposit or forgo canceled checks," McBride said.

Experts say consumers should consider whether they expect to have a low balance, how often they write checks and whether they like using ATMs, the telephone, the Internet or tellers. Consumers also should read the fine print.