(Reuters) - Equipment rental company Ashtead Group Plc said on Tuesday its full-year profit rose 17% as its U.S. Sunbelt business benefited from higher demand for industrial gear.The FTSE-100 company, which rents out diggers, construction tools and other equipment, said underlying pretax profit rose to 1.11 billion pounds ($1.39 billion) in the year ended April 30, from 927.3 million pounds a year earlier. Total revenue at Sunbelt U.S. increased 20% to $4.99 billion from a year earlier, driving..