SAN FRANCISCO — In an order that could have ramifications for other manufacturers, the Federal Circuit ruled that diabetes testing company LifeScan Inc. gave away its ability to assert a patent against competitors when it distributed its blood glucose meters to health care providers for free.

Though the Johnson & Johnson subsidiary made no money on such transactions, it still gave up its right to assert patent claims against companies that design test strips for use with its meters, the U.S. Court of Appeals for the Federal Circuit found in a 29-page decision issued Monday. The Federal Circuit denied LifeScan’s bid for a preliminary injunction blocking the sales of its competitors’ test strips, reversing a decision from U.S. District Judge Edward Davila of the Northern District of California.