By Andrew Chung

WASHINGTON, Feb 24 (Reuters) - The U.S. Supreme Court on Monday handed a victory to Walgreens, turning away an appeal by a fired former Florida employee of the pharmacy chain who asked not to work on Saturdays for religious reasons as a member of the Seventh-day Adventist Church.

The justices declined to review a lower court ruling in Darrell Patterson's religious discrimination lawsuit that concluded that his demand to never work on Saturday, observed as the Sabbath by Seventh-day Adventists, placed an undue hardship on Walgreens.

Patterson, who had trained customer service representatives at a Walgreens call center in Orlando, was fired in 2011 after failing to show up for work on a Saturday for an urgent training session.

The case tested the allowances companies must make for employees for religious reasons to comply with a federal anti-discrimination law called Title VII of the Civil Rights Act of 1964. The law prohibits employment discrimination based on race, color, religion, sex and national origin.

Under Title VII, employers must "reasonably accommodate" workers' religious practices unless that would cause the company "undue hardship." (Reporting by Andrew Chung; Editing by Will Dunham)