Earlier this month, Slim Jim-maker Conagra Brands CAG.N said it would have to raise product prices further to offset a bigger-than-expected increase in costs. By Uday Sampath Kumar and Praveen Paramasivam Jan 21 (Reuters) - Executives at U.S. companies including Monster Beverage and American Airlines have stressed on higher costs for everything from labor to raw materials in the last few days, pointing to more price increases as profit margins come under severe strain. "We've got inflationary pressures all around," Hilton Schlosberg, co-chief executive officer of energy drink maker Monster Beverage Corp MNST.O, said on a recent investor call.