Processing port requests has become a lengthy procedure, as the companies losing their customers must do more paperwork. That creates a barrier for the companies receiving the clients, which may lose customers that are unwilling to endure waits as short as two-and-half hours or as long as two weeks.

"In wireless markets, there are no market forces that will drive efficient regulation," said Ted Schremp, senior vice president and general manager of Charter Telephone. "All the incoming telephone companies are at a loss. We believe that market forces are not sufficient."

Variations in the length of the procedure tend to correlate with the type of port. Wireless-to-wireless moves tend to be processed faster, while wireline-to-wireless porting takes more time, industry officials say.

Banks noted that telecommunications companies require only three to four information fields for wireless-to-wireless ports but up to 100 fields for wireline-to-wireless ports, even though only 25 of the fields must be completed to process a request.

Variations also exist based on company size. Larger companies, which tend to get more port requests, have fully automated processes, while smaller companies that must do the work manually deal with higher costs.

Schremp said that while Charter is a relatively small company, it has been able to comply with FCC regulations for a time. "We're not automated and we abide by the four-day rule without any problems," he said.

Commerce Chairman Daniel Inouye, D-Hawaii, and the panel's top Republican, Sen. Ted Stevens of Alaska, questioned whether the bill is necessary and would encourage companies to create more efficient processing.

While the FCC could address the problem through regulation or incentives, all the panelists agreed that Congress could help by increasing pressure on the FCC to act on the issue.

Stevens also questioned whether the problems that have arisen with Internet phone services such as Vonage should be addressed by the bill. Consumers can keep their numbers while switching to wireless services, but under current rules they cannot do so when using Internet telephony.

Two federal advisory committees, the North American Numbering Council and the Ordering and Billing Forum, were asked in 2004 by the FCC to develop ways to improve number porting but have yet to deliver, said Chris Guttman-McCabe, vice president for the wireless group CTIA. He said streamlining porting operations is essential to encouraging growth.

The bill would establish timelines for different classes of number portability and require the exchange of data so there is a unified process for transferring phone numbers.