Comverse Technology Inc.’s former general counsel, William Sorin, will plead guilty in the stock-options backdating prosecution that has ensnared his onetime boss, fugitive Jacob Alexander, court papers say.

The docket in the case said today that a “Guilty Plea”is set for Mr. Sorin at 12:30 p.m. tomorrow before U.S. District Judge Nicholas Garaufis in Brooklyn, New York.

Mr. Sorin is the second Comverse executive to admit guilt in the case. He may become a witness against Mr. Alexander, now in Namibia fighting extradition. David Kreinberg, the company’s former finance chief, pleaded guilty last month and implicated Mr. Alexander, the former chief executive officer of New York-based Comverse, the biggest maker of voicemail software.

“The government appears to be working in concentric circles, moving inward and tightening the noose against the ultimate target of their investigation, Mr. Alexander,” a former federal public defender now in private practice in New York, Charles Ross, said.

A spokesman for U.S. Attorney Roslynn Mauskopf of Brooklyn, Robert Nardoza, wouldn’t say what crimes Mr. Sorin would plea to. Mr. Sorin is 56 and a Harvard Law School graduate who lives in Manhattan, according to the U.S. Attorney’s office and court papers. His lawyer, James Brochin, couldn’t be immediately reached for comment.