A US Senate panel has backed a sweeping healthcare overhaul.By gaining the support of an influential Republican, the key finance committee gave the green light to the reform in a 14 to 9 vote. Senator Olympia Snowe becoming the first Republican in Congress to back a healthcare bill. It’s a major victory for President Barack Obama who had made it his top domestic priority. He’s been facing fierce resistance from the private healthcare industry. The S&P Managed Health Care index of large health insurers was down 2.3 percent in afternoon trading.