NEW YORK (Reuters) - A federal agency sued a New York customer service provider on Wednesday after allegations the company forced employees to pray, thank God for their jobs and say "I love you" to managers and colleagues at work, and fired those who protested.

The Long Island-based United Health Programs of America and its parent company, Cost Containment Group, required workers to practice a spiritual belief system called Onionhead while on the job, in violation of their civil and religious rights, the U.S. Equal Employment Opportunity Commission said in the complaint.

The company fired several employees who refused to adhere to the Onionhead doctrine, which was created by the aunt of the company's owner, the complaint said.

In one case, an IT project and account manager was disciplined after she complained to management in 2010 that she was Catholic and did not want to participate in the spiritual activities, according to the complaint.

A month after she complained, the employee was removed from her office and relocated to an open customer service area, while a large statue of a Buddha was placed in her former office. She protested to the owner that the move amounted to a demotion and was fired, the complaint said.

"While religious or spiritual practices may indeed provide comfort and community to many people, it is critical to be aware that federal law prohibits employers from coercing employees to take part in them," Sunu Chandy, senior trial attorney at the commission, said in a statement.

The commission is seeking back pay with interest and unspecified damages for the fired employees, and an injunction against the company from further religious requirements.

Representatives for United Health Programs of America and Cost Containment Group could not be immediately reached for comment.

(Reporting by Curtis Skinner; Editing by Edith Honan and Peter Cooney)