'A North Carolina State University professor who had been selling audio recordings of his lectures online was asked to stop on Wednesday after a university dean raised objections.

Since late August, Robert L. Schrag, a professor of communication, had been selling lectures from his classes to students and others through a Web site called Independent Music Online. The lectures, in MP3 format, sold for $2.50 each, with $1.00 going to Mr. Schrag and $1.50 going to the music Web site.

But Mr. Schrag said he had asked the operator of the site to take down his lectures after Toby L. Parcel, dean of the university's College of Humanities and Social Sciences, told him that the practice bothered her. Mr. Schrag said he agreed to halt the sales -- at least temporarily -- while Ms. Parcel investigated whether the university would allow professors to sell their lectures. Mr. Schrag said the head of the department of communication, Craig Allen Smith, had previously given him the go-ahead to market the recordings.

"I want the university to be clear where it is on this and address the issues," Mr. Schrag said on Thursday, adding that other professors at the university might also be interested in selling their course materials online. "I'm still recording. I'm still archiving, and I'm hoping we'll be able to go back up with it," he added.

Professors at North Carolina State University have sole ownership of materials that they produce in their classrooms, he said.

Still, his unusual endeavor started attracting controversy after the student newspaper, the Technician, ran an article about it on Wednesday, and also published an editorial criticizing the practice. The editorial said college students should be able to listen to recordings of professors' lectures free. The popular technology Web site Slashdot picked up the news article, and the university suddenly found itself at the center of a debate about what professors are entitled to do with their lecture material.

Mr. Shrag's lectures were delivered to his Communication and Technology class, which is a core course for communication majors. Before the music Web site took down his material, Mr. Schrag said he had five or six lectures for sale.

Patrick Hefner, the president of Independent Music Online, said three people had purchased 12 lectures by Mr. Schrag, generating $30 for the Web site. Mr. Schrag said he made $11 from the sales.

Mr. Schrag, who was honored with a teaching award in 1993, said he decided to charge for the lectures because recording them "takes effort and it's beyond what I ordinarily do." Engineering and science professors often receive compensation for the intellectual material they produce, Mr. Schrag said, so why shouldn't humanities and social sciences professors be paid as well?

"We're talking about the price of a draft beer," he said. "You go to a concert. Your tuition buys you access to the concert, it doesn't buy you the CD."

Mr. Schrag said he surveyed his students anonymously on Thursday -- about 150 in all -- about whether they thought he should offer his lectures for sale. Of the 119 students who responded, 99 said yes, 16 said they didn't care one way or the other, and four said the lectures should be free.

Mr. Schrag said his lectures are meant for three audiences: students who are motivated to do well in the course and want access to supplemental material, international students who may have difficulty understanding English, and students who would prefer to skip class.

"If a student doesn't want to be there, I don't want them there," Mr. Schrag said. "I want them to go away because they degrade the educational experience for the other students around them."

Ms. Parcel could not be reached for comment on Thursday. But a spokesman for the university, Keith Nichols, said it was "in everybody's best interest" for Mr. Schrag to stop selling his lectures while the university looked into the propriety of the practice.'