Mexico’s Corona Light is the most popular imported light beer in the United States, but you can’t get it south of the border, where beer drinkers order their brews in pairs yet rarely reach for a low-calorie alternative. Mauricio Brocado, a Mexico City analyst who tracks Mexican brewers for brokerage firm Deutsche-Ixe, said light beer accounts for less than 2 percent of the country’s $3 billion domestic beer market. At the same time, Corona Light had $47 million in sales in the United States in the first half of this year, up 9 percent from a year earlier, said Bump Williams, of Information Resources, an international marketing research organization. Mexico’s biggest brewers, Corona’s manufacturer, Grupo Modelo, and the brewing unit of bottler Fomento Economico Mexicano (FEMSA) are trying to convert more Mexicans into light beer drinkers, with ad campaigns that give the brew a sharper, edgier image and that convey the idea that less really is more. And it’s quite a challenge. Demand for light beer is so minuscule that Corona Light — the 14th-best-selling beer in the United States and among America’s fastest-growing imported brews, according to Williams — is produced for export only. Mexico’s bestselling light beers are Modelo Light and FEMSA’s Tecate Light. “We look at light with a certain amount of distrust,” Brocado said. “Those who drink beer, drink beer — not something seen as less than a normal beer.” Brewers in Mexico are dealing with the same marketing issues that American beer makers had decades ago, when they were struggling to get consumers to try light beer.