WASHINGTON (Reuters) - Sales at retailers barely rose in April as the boost from an unseasonably warm winter faded, pointing to some loss of momentum in consumer spending early in the second quarter.

Retail sales edged up 0.1 percent, held back by a decline in receipts from building materials and clothing stores, the Commerce Department said on Tuesday. That was the smallest gain since December when sales were flat.

March's sales were revised slightly down to show a 0.7 percent rise rather than the previously reported 0.8 percent increase. Economists polled by Reuters had expected retail sales to gain 0.2 percent last month.

In the 12 months to April, sales rose 6.4 percent.

(Reporting by Lucia Mutikani; Editing by Chizu Nomiyama)