U.S. debt limit increase would extend until March 2017

WASHINGTON (Reuters) - U.S. borrowing authority would be extended until March 2017, beyond the Obama administration, under a deal being negotiated by congressional leaders and the White House, according to a U.S. House of Representatives source. As part of a parallel measure to fund government programs through Sept. 30, 2017, negotiators also aim to stop an increase in Medicare Part B premiums that is otherwise due to start soon. This is the supplemental health insurance program mainly for the elderly. While a final deal has not yet been reached, negotiators hope to nail it down later on Monday and begin moving it through the House of Representatives, according to the source, who asked not to be identified. (Reporting By Richard Cowan; Editing by Sandra Maler)