Horacio Arturo Ruiz Cortes came to Pittsburgh from Mexico in 1993 and found work as a busboy at Mallorca Restaurant on the South Side, rising through the ranks until he became the general manager of Mallorca's Marbella Restaurant in Cleveland.

When he knew he couldn't go any further, Mr. Ruiz said he approached the owners of Mallorca, Antonio Pereira and Fausto Simoes, with the concept for a new restaurant, Ibiza Tapas and Wine Bar. It opened in 2005, next door to Mallorca.

Shortly afterward, it seems, things went awry, according to a lawsuit filed this week in Allegheny Common Pleas Court against Mr. Simoes and Mr. Pereira by Mr. Ruiz.

Mr. Ruiz alleges that each of the three agreed to contribute an initial capital investment of $100,000, and that Mr. Ruiz would finance his part over time by taking a reduction in his annual salary. Mr. Ruiz also said he agreed to forfeit revenues generated by Ibiza until Mr. Pereira and Mr. Simoes recovered their initial investment, and that each would hold an equal share in the business on the condition that Mr. Ruiz obtain a permanent resident card, which he received on Jan. 25, 2006.

Nearly six months later, however, Mr. Pereira terminated Mr. Ruiz's employment, with no compensation for his ownership share. In his six-count lawsuit against the two men, Mr. Ruiz, who now serves as general manager at UUBU6 (pronounced "Ooh Boo Six") on the South Side, is seeking a minimum of $25,000 to cover his losses, plus legal fees.

His lawyer, Bruce Fox, of Obermayer Rebmann Maxwell & Hippel, Downtown, said that Ruiz was mistreated because of his immigrant status. "He worked very hard, and he was taken advantage of," Mr. Fox said, adding Mr. Ruiz's new citizenship status has "empowered him to take action."

Although he has yet to be served with the lawsuit, Mr. Pereira yesterday said Mr. Ruiz used to work for him but was discharged because he "was buying things in the name of the company without being a partner."

He further denied Mr. Ruiz's share in Ibiza. "When you are a partner, you've got to put some money into a business," he said. "He never put a penny into my business."