WASHINGTON, June 15 (Reuters) - The U.S. Supreme Court on Monday delivered a watershed victory for LGBT rights, ruling that a landmark federal law forbidding workplace discrimination protects gay and transgender employees.

The 6-3 ruling represented the biggest moment for LGBT rights in the United States since the Supreme Court legalized same-sex marriage nationwide in 2015. In the new ruling, the justices decided that gay and transgender people are protected under Title VII of the Civil Rights Act of 1964, which bars employers from discriminating against employees on the basis of sex as well as race, color, national origin and religion. (Reporting by Lawrence Hurley; Editing by Will Dunham)