Features come and go with startling speed in the still-evolving online banking market, but few seem to make as many round trips as account aggregation.

At Wells Fargo & Co. alone, it has been tried, dropped, retried, and dropped again. When the San Francisco company debuted a set of online financial management tools last week, it had an opportunity to bring back aggregation, but it did not.

Teddy De Rivera, the head of online banking and investments in the Internet services group, said the decision reflects a sense at the company that the upside to offering aggregation is outweighed by the risk it introduces in the customer relationship.

Aggregation does not fit with the goal of tying Wells Fargo tools to Wells Fargo accounts, Mr. De Rivera said in an interview last week. "Part of the reason we're doing this, to be candid, is because it's part of our broader company strategy around making sure we can encourage customers to use the tools that we have," he said.

The My Spending Report feature on its Web site has long allowed customers to categorize their spending and view it in charts. The new Budget Watch features let people build budgets for various spending categories or set savings goals, and they automatically subtract spending from a given category's budget over the course of the month.

Such capabilities are also offered by several nonbank sites that aggregate information from users' various banking and brokerage accounts and help people monitor their overall financial situation. Aggregation lets people view account details from multiple financial companies,

In contrast, Mr. De Rivera said the Wells tools, which were made available to users last month, will include only information from Wells accounts.

Customers had asked for something that could help them set monthly budgets and savings goals, and the tools that were already available through My Spending Report were "a little backward-looking," he said. Customers could see where their money had gone, but they could not use the site to set up plans for future spending.

Future additions to My Spending Report will continue along this theme, he said, with tools that could help customers pay down their debts, for example. The goal is to encourage people to pay more attention to their Wells accounts, and possibly increase cross-sales, by showing people how various banking products can be linked, Mr. De Rivera said.

There was little customer demand for aggregation, he said.

Observers said that aggregation is the only way a nonbank financial management site can offer users any data, but the lack of aggregation is not likely an issue for a banking company of Wells' size.

Wesabe Inc., a San Francisco company that operates a financial management site, said last week that 46.7% of its users with Wells accounts do not have any other bank account enrolled at the site. Among those users, 60.6% have more than one Wells Fargo account. Sitewide, 60.8% of users have either a single account enrolled or multiple accounts at the same financial company.

Ron Shevlin, a senior analyst at Aite Group LLC of Boston, said in an interview that Wells has no immediate need to bring back aggregation.

"The lack of aggregation is not a big barrier for Wells Fargo at this point in time," he said. "Keep in mind we're talking about Wells Fargo here, and of all the banks in the industry" that share such data, "they're probably the leaders in having the most number of products per customer."

Taking that into consideration, adding outside accounts may not improve the utility of the tools Wells offers today, Mr. Shevlin said. "What are they going to gain by aggregation? A couple of investment accounts? Maybe 401(k)? Those aren't the type of accounts that typically play in the budgeting and day-to-day financial management perspective."

Even at some of the nonbank aggregation providers such as Wesabe, customers are more interested in the social networking aspects of the site than the aggregation feature, he said. "It's not the majority of people who want to analyze their data to death."

However, growing interest in sites operated by companies like Wesabe, Mint Software Inc., Geezeo Inc., has prompted Wells to reconsider its views on aggregation.

"Because of tools like that, there's been much more interest in aggregation; not just to be able to look at your overall balances, but also to be able to manage spending that you're doing across all of your accounts, regardless of if they're just at Wells Fargo," Mr. De Rivera said.

Nevertheless, Wells has no current plans to reintroduce aggregation technology.

Wells offered aggregation capabilities first through an outsourcing deal with Yodlee Inc. of Redwood City, Calif., and then in-house through software developed by Teknowledge Corp., now part of Intuit Inc. of Mountain View. But it has not offered aggregation since 2005.

Mr. De Rivera said the choice to back away from aggregation was made mainly because of lack of customer interest. "The old aggregation tools were just simply not used very much by customers. The traffic we were getting was very, very low."

Citigroup Inc. dropped its aggregation service the same year, and in 2004, City National Corp. of Beverly Hills dropped its service after a six-month test. The companies said only a small portion of their customer base had signed up for the services.

Bank of America Corp. offers aggregation through Yodlee. This year the Charlotte company led an investment round in the vendor to promote its bill payment service.

In addition, financial companies that use Intuit online banking software can offer aggregation through its recently launched FinanceWorks financial management platform.

Edward Woods, a senior analyst for Celent, the Boston financial research arm of Marsh & McLennan Cos. Inc., wrote in an e-mail that part of the reason aggregation has not taken off at bank sites is that bankers have done a poor job promoting it.

Many online banking sites put their aggregation features at the end of a long list of other online services, rather than integrating it into their main services, he wrote.

"In the early days of aggregation many mistakes were made and lessons learned. … Aggregation alone will solve little and will appeal to few," he wrote. "The next wave of online banking aggregation will prove to be a much more successful venture" as it integrates tools such as those Wells and others have built to help users track their budgets.

As these services mature, consumers with accounts at several banks will favor the one that provides the best financial management tools and will view that bank "as 'my bank, my primary bank,' " Mr. Woods wrote. "I might have other accounts elsewhere, but it is this bank that I have a connection with."