Yum! Brands ( YUM) reported a 21% increase in first-quarter earnings Wednesday, led by strong results at the company's Taco Bell restaurants. In the quarter ended March 20, Yum! Brands earned $142 million, or 47 cents a share, which was ahead of analysts' consensus for 45 cents a share. The results compared with a profit of $117 million, or 39 cents a share, a year ago. Revenue rose to $1.97 billion, from $1.8 billion a year ago. The company said higher same-store sales and continued development of new, higher-volume restaurants drove sales. U.S. blended systemwide same-store sales increased 4%. "In the U.S., Taco Bell continues to generate strong, positive same-store-sales results driven by product news and steady operations improvement," the company said in a statement. "Pizza Hut results were driven by the successful introduction of the innovative 4forAll Pizza. As expected, KFC's sales performance continues to be negative." Shares of the Louisville, Ky.-based-company were moving up 0.03% to $36.11 in after-hours trading, after closing down 51 cents, or 1.4%, at $36.10. Yum! Brands noted that higher U.S. commodity prices negatively affected the U.S. restaurant margin by 0.6 percentage point. Expansion of the company's international brands -- KFC and Pizza Hut -- and positive system same-store sales drove international revenue, system-sales and operating profit increases, the company said. Total international revenue was $673 million, up from $550 million a year ago. Regarding KFC, the company said it expects positive same-store sales in the back half of the year as KFC executes a major brand re-launch, which includes the roll out of a new menu board, a new advertising campaign and new products. "It is also important to note that while second-quarter international system-sales growth will be adversely affected by the avian flu, Chinese sales trends have fully recovered, and we expect this key market will continue to report rapid growth in 2004," Yum! Brands said.