Mississippi would lose most of its remaining regulatory authority over AT&T under a bill that passed in the House of Representatives.
Telephone service in Mississippi was mostly deregulated in 2006, ending the Public Service Commission's traditional power to set rates.
House Bill 825 would remove remaining PSC rate-making authority over 30,000 local-only landlines.
The PSC and some consumer advocates fought the bill.
The measure also ends AT&T's obligation to serve as company of last resort for landline customers in its traditional territory, and requirements that it file service and financial data with the PSC.
AT&T says the requirements are unfair burdens that competitors don't bear.
The Senate deleted a study committee to examine what phone companies pay each other for switching calls. The House agreed to the change, 86-34.