By Dan Levine SAN FRANCISCO (Reuters) – A U.S. judge on Thursday rejected Apples request for a permanent sales ban in the United States against some older Samsung smartphones, a key setback for the iPhone maker in its global patent battle. U.S. District Judge Lucy Koh in San Jose, California, ruled that Apple Inc had not presented enough evidence to show that its patented features were a significant enough driver of consumer demand to warrant an injunction. Apple and Samsung Electronics Co Ltd have been litigating for nearly three years over various smartphone features patented by Apple, such as the use of fingers to pinch and zoom on the screen, as well as design elements such as the phones flat, black glass screen. Apple was awarded more than $900 million by U.S. juries but the iPhone maker has failed to sustain a permanent sales ban against its rival, a far more serious threat to Samsung, which earned $7.7 billion last quarter.