Nearly half the state attorneys general have condemned legislation that would overhaul the nation's financial services industry, saying it would deprive consumers of a say in how their account data, health records and other personal information are used.

The legislation would rewrite Depression-era laws to expand the ability of banks, securities firms and insurance companies to merge with one another and share customer names, addresses and account data to market new services and products. Similar versions of the law were approved by the House and Senate earlier this year.

While industry advocates say the reforms would benefit customers by expanding services and lowering costs, consumer and privacy advocates have warned the legislation would make it impossible for individuals to control access to information that traditionally has been considered off limits for sharing.

On Monday, attorneys general in 21 states agreed with consumer advocates, saying in a letter to leaders of the House and Senate banking committees they believe the proposals "will not provide adequate protection for private financial and medical records."

The states' top law enforcers urged lawmakers to require companies to obtain consumer permission before "using, sharing or selling" their information for any purpose "other than legitimate law enforcement purposes."

"Consumers in our states are extremely concerned about privacy issues," the letter said. "The rapid development of technology has permitted the creation and manipulation of ever larger and more complex data bases. Revision of the structure of the financial service industry will almost certainly hasten the process."

The letter was delivered as leaders from the House and Senate banking committees met to reconcile differences in two similar proposals. It was drafted despite heavy lobbying from industry officials, who pressed the attorneys general to withhold comment and warned restrictions on the use of information could curb the benefits of reform.

John Byrne, senior counsel at the American Bankers Association, said the proposal by the attorneys general goes too far and might make it difficult for banks to offer some services and investigate fraud. "We obviously believe very strongly it's misguided and will have a harmful effect on modernization," he said.

But privacy activists praised the letter. Deirdre Mulligan, staff counsel at the Center for Democracy and Technology, a Washington-based advocacy group, said that "this has been identified as a critical consumer protection issue."

"Financial privacy shouldn't be an afterthought," she said.