A Dorchester man has been convicted of manslaughter for fatally stabbing a co-worker who ridiculed him about his failed attempts to date a waitress at the hotel restaurant where they both worked.

Ivan Lorenzo Sosa was found guilty Tuesday in the Sept. 16, 2006, death of 30-year-old Carlos Borrero Jr. of Chelsea. Sosa was charged with second-degree murder, but a Suffolk Superior Court jury convicted him of the lesser charge of voluntary manslaughter. He was sentenced to serve 8 to 12 years in prison.

Both men worked in the upscale Turner Fisheries restaurant at the Westin Copley Place Hotel in Boston. Prosecutors said the 39-year-old Sosa grabbed a knife and stabbed Borrero repeatedly in the kitchen in front of other workers who tried to stop him.