Thomson ReutersMarch 7, 2013 02:15
* Democratic-led panel expected to back four bills
* But unclear which if any of them will win Senate approval
* Dispute arises over background checks for gun owners
By Thomas Ferraro
WASHINGTON, March 7 (Reuters) - Less than three months after the Connecticut school shooting, a campaign to tighten U.S. gun laws that is backed by President Barack Obama will go to its first votes in Congress on Thursday when a U.S. Senate panel meets.