A headmistress and teacher at an exclusive private Manhattan Montessori school, accused of having sexual relations with two young teen students, was convicted Thursday of sodomizing one of them when he was 13.

Lina Sinha, 40, showed no emotion as the jury foreman reported a partial decision of 11 guilty and two not guilty verdicts on various other charges. The jurors had reported earlier they were deadlocked on the six rape counts against her.

Assistant District Attorney Rachel Hochhauser told the judge her office intended to retry Sinha on the six rape counts.

State Supreme Court Justice Carol Berkman ordered Sinha, who was free on $50,000 bail, jailed on $3.5 million bond. The judge noted the lengthy sentence Sinha faces and her family's substantial assets as reasons for raising the bail.

The judge scheduled sentencing for April 19.

When Sinha was first arrested, prosecutors told the court she was a flight risk because she has ties to India.

Sinha's lawyer, Gerald Shargel, said later outside court, "We're very confident about the appeal. We intend to pursue it as expeditiously as possible." He said he expected his client's parents to come up with a bail package.

The key witnesses against Sinha were the two students she was accused of seducing, the first student in June 1996, when he was 13 and an eighth grader, and the second when he was 12 and a seventh grader.

The first student, now a 24-year-old police officer, tried to end the affair in 2004, prosecutors said, and the teacher tried to exact revenge by reporting to police at least 10 times that he raped a young girl and brutally assaulted Sinha.

In October 2005, police charged Sinha with raping him.

Meanwhile, prosecutors said, Sinha started a sexual relationship in January 2001 with the second student. That boy, now 19 and on probation from his last arrest, said he had sex with Sinha at least six times when he was 12.

Sinha was arrested on charges of raping him in May 2006.

Prosecutors said Sinha tried to bribe the youth to lie to investigators by buying him sneakers and a prepaid telephone and by giving him $400 cash.

Sinha has been a teacher for 16 years at the Montessori International School of New York, which was established by her parents in 1969 and encourages students to learn and develop their creativity at their own pace. The parents own two similar schools in the city.

Besides the sodomy and witness bribery counts, Sinha was convicted on several counts of criminal impersonation and falsely reporting an incident, all misdemeanors punishable by up to a year in jail.

The Montessori teaching method was founded in Italy a century ago. It encourages independent learning and promtes the idea that children can teach themselves with little help from adults.