SEATTLE—T-Mobile USA Inc. and its parent company, Deutsche Telecom A.G., have been ordered by the U.S. Department of Labor to pay $345,972 to a worker allegedly fired for being a whistle-blower. Bellevue, Wash.-based T-Mobile said it plans to appeal.

The Department of Labor’s order resulted from an investigation into alleged violations of the whistleblower protection provisions of the Sarbanes-Oxley Act of 2002. The investigation substantiated the affected employee’s complaint, which alleged termination for raising concerns about the possibility of millions of dollars in fraudulent roaming charges being levied on hundreds of international corporate customers.

T-Mobile says it plans to appeal the award and says the preliminary conclusion is incorrect and was not based on the evidence.

In addition to requiring T-Mobile to immediately reinstate the whistleblower, OSHA’s order requires the company to pay $244,479 in back wages and interest, $65,000 in compensatory damages and $36,493 in attorney’s fees. The company also must provide a neutral employment reference, post a notice about the Sarbanes-Oxley Act’s whistleblower provisions and train employees on these provisions.

The actual allegations raised by the unnamed employee would have to be investigated by the Securities and Exchange Commission and could not be acted on by the Department of Labor.