A former theater agent who tricked his friends into backing a nonexistent Broadway play that he said would star the actress Lupita Nyong’o pleaded guilty on Wednesday to stealing about $200,000 from investors.

The former agent, Roland Scahill, 42, pleaded guilty to grand larceny and fraud charges in State Supreme Court in Manhattan under an arrangement that calls for him to be sentenced to six months in jail and five years’ probation, according to court papers.

As part of the deal, Mr. Scahill must repay $189,000 over the next six months to the investors he bilked. He must also receive psychiatric treatment.

“We are pleased to have brought his larcenous scheme to a grand finale,” the Manhattan district attorney, Cyrus R. Vance Jr., said in a statement.