A Senate panel on Tuesday approved a bill drafted by AT&T that would further diminish state regulation of the company and allow it to end basic phone service in less profitable parts of its service areas. Opponents said Senate Bill 12 would let the state's three major phone carriers — AT&T, Windstream and Cincinnati Bell — abandon rural communities where poor and elderly residents depend on basic land-line service, including operator assistance and 911. AT&T hopes to force those residents to upgrade to more expensive service plans they don't need and can't afford, such as wireless or broadband, opponents said.