Pennsylvania- A former Wharton School professor pleaded guilty in federal court yesterday to five child-pornography charges, including videotaping sex acts between himself and a 16-year-old Brazilian boy.

The guilty plea by Lawrence Scott Ward, 66, a former marketing professor at the University of Pennsylvania school, stems from his arrest on Aug. 9, 2006, at Dulles International Airport in Virginia, where officials found DVDs and child pornography on his laptop. Ward pleaded guilty in February to trafficking in child pornography, and is serving a 15-year sentence in federal prison.

More charges were filed after federal agents investigated further.

When detained at the airport, Ward had been on his way to Sao Paulo, Brazil, known as a center of child-sex tourism, according to the National Center for Missing and Exploited Children. Pornography was later found in Ward’s office at the University of Pennsylvania.

Ward will be sentenced on the latest charges on Feb. 19. He faces at least 15 more years but could receive life imprisonment.

The sentence will depend on whether the judge accepts the prosecution’s case that Ward lied to authorities in 2006 when he tried to secure a visa for the Brazilian teenager.

Federal prosecutors say Ward used his Wharton e-mail account from Jan. 31 to June 6, 2006, to “persuade, induce, entice and coerce” the teen to have sex with him.

According to the indictment, Ward provided gifts, housing and thousands of dollars to the teen and his destitute mother, and threatened to withdraw his support if the teen did not show Ward “love and respect, especially in bed.”

In summer 2006, Ward invoked his Wharton professorship and sizable bank account to try to secure a visa for the teen, whom he wanted to visit him on Cape Cod, Mass.

When the State Department denied the visa, Ward allegedly tried to persuade authorities that the boy’s family was “reasonably wealthy by Brazilian standards” and tried to set up an account in the boy’s father’s name.

At the time of his arrest, Ward was a Wharton professor emeritus who had retired in 2005 but who had been slated to teach a marketing course in the fall.

In 1999, Ward was accused of soliciting sex from an undercover state trooper posing as a 15-year-old boy. He was fined $2,500 and given five years of probation.