NEW YORK, June 28 (Reuters) - U.S. stocks fell on Thursday but ended above session lows on talk of progress among European leaders in resolving the region's debt crisis, while the Supreme Court's ruling upholding a landmark healthcare law hit big health insurers.

Based on the latest available data, the Dow Jones industrial average was down 24.90 points, or 0.20 percent, at 12,602.11. The Standard & Poor's 500 Index was down 2.84 points, or 0.21 percent, at 1,329.01. The Nasdaq Composite Index was down 25.83 points, or 0.90 percent, at 2,849.49.