By Sarah N. Lynch

WASHINGTON, June 26 (Reuters) - The U.S. Supreme Court agreed on Monday to take up a case that promises broad implications for when corporate insiders who blow the whistle on alleged misconduct can be shielded from retaliation by their employers.

The justices will hear Digital Realty Trust Inc's appeal of a lower court ruling in favor of an executive who the San Francisco-based company fired after he complained internally about alleged misconduct by his supervisor but never reported the matter to the U.S. Securities and Exchange Commission.

The case hinges on the SEC's whistleblower protection rules required by the 2010 Dodd-Frank Wall Street reform law.

Those rules, which were adopted in 2011, prohibit corporate employers from retaliating in any way against whistleblowers who try to report allegations of securities law violations.

They also give the SEC the power to offer monetary awards to whistleblowers whose tips lead to successful enforcement actions.

Digital Realty Trust argues that the anti-retaliation protections do not apply to people who fail to report their allegations to the SEC because the law defines a whistleblower as a person who reports possible securities violations to the SEC.

(Reporting by Sarah N. Lynch; Editing by Will Dunham) ((sarah.n.lynch@thomsonreuters.com; 202-354-5831;))