Gap Inc. reported that May net sales increased 4 percent compared with last year. Net sales for the four-week period ended May 31, 2014 were $1.27 billion compared with net sales of $1.22 billion for the four-week period ended June 1, 2013.   "We delivered a positive comp to start the second quarter, building on last May's strong performance," said Glenn Murphy, chairman and chief executive officer, Gap Inc.   May Comparable Sales Results Gap Inc.'s comparable sales for May 2014 were up 1 percent versus a 7 percent increase last year.    Comparable sales by global brand for May 2014 were as follows: -Gap Global: negative 3 percent versus positive 8 percent last year -Banana Republic Global: positive 3 percent versus flat last year -Old Navy Global: positive 2 percent versus positive 9 percent last year    Gap Inc. is a leading global retailer offering clothing, accessories, and personal care products for men, women, and children under the Gap, Banana Republic, Old Navy, Piperlime, Athleta, and Intermix brands.    Fiscal year 2013 net sales were $16.1 billion. Gap Inc. products are available for purchase in more than 90 countries worldwide through more than 3,100 company-operated stores, over 350 franchise stores, and e-commerce sites.