The chain said Friday that sales in the new year are trending “modestly negative” as the broader fast-food industry fights to attract cash-strapped diners with cheap eats. To address the intensifying focus on value from competitors, Steve Wiborg, president of Burger King’s North America operations, noted the company launched a limited-time offer for a Junior Whopper for $1.29 this week. Although Burger King will continue to offer premium items,

