The U.S. stocks struggled to stay in positive area on Tuesday after report showed sales of existing homes fell less than expected in February. The National Association of Realtors said in its latest report that sales of previously occupied homes fell 0.6 percent in February to an annual rate of 5.02 million units. The reading topped analysts' estimate of 5 million. However, it still raised concerns about the strength of the housing market after three straight drops in monthly sales. Major indexes ended higher on Monday, buoyed by the rally among health-care stocks after the House of Representatives passed the health care bill on Sunday night, which removed uncertainties and could have a far-reaching impact on insurance and pharmaceutical sectors. The Dow Jones industrial average gained 27.29, or 0.25 percent, to 10,813.18. The Standard & Poor's 500 index added 0.26, or 0.02 percent, to 1,166.07 and the Nasdaq edged up 1.57, or 0.07 percent, to 2,396.97. 