NEW YORK, Feb 28 (Reuters) - US Airways Group (U) has agreed to sell 29 gates at Baltimore/Washington International airport for about $4.3 million after cutting back on its services in the wake of the Sept. 11 attacks. Maryland Aviation Administration said it has agreed to pay US Airways for early termination of its lease on 17 of its 24 jet gates and 12 of its 18 commuter gates at the airport. Maryland state officials will hand over the some of the gates to Southwest Airlines (LUV) and UAL Corp.'s (UAL) United Airlines and allow other carriers to pick up the remaining gates. After last year's attacks on the United States, Arlington, Virginia-based US Airways discontinued its MetroJet service, which had 49 daily flights operating out of BWI airport. Before the attacks, US Airways operated a total of 148 daily flights from the airport and it now operates about 76 daily flights. US Airways shares closed Thursday trading down 3 cents at $5.32 on the New York Stock Exchange. The stock has lost about 87 percent over the last year and is off about 54 percent since the attacks which sharply curtailed travel demand