A Montgomery County middle school teacher was convicted last night of fondling and kissing a 14-year-old student on school property during two separate incidents in May.

A Montgomery County Circuit Court jury deliberated 8 1/2 hours before finding David G. Reitz guilty of two counts of child sex abuse and two counts of fourth-degree sex offense.

Reitz, 40, a science teacher at Ridgeview Intermediate School in Gaithersburg, was accused of fondling the breast of an eighth-grade student on May 8 and 9 during the showing of a film on volcanoes. Reitz also was accused of kissing the girl the next day while he was alone with her.

The jury acquitted Reitz of one count each of child sex abuse and fourth-degree sex offense relating to the May 8 incident.

During the four-day trial before Judge DeLawrence Beard, jurors heard testimony from the defendant, the girl, school administrators and several students.

Reitz, who has been on administrative leave without pay since September, denied the allegations, saying, "I never touched her intentionally . . . maybe inadvertently." Reitz, who described himself as a "relaxed, casual" teacher, said he often hugged his students to offer reassurance or praise.

The girl testified Reitz put his arms around her while in class during the first two incidents and began stroking her arms and fondling her breasts.

A classmate testified she witnessed the second incident.

The next day, the girl said, she contacted a school counselor to discuss the incidents but an appointment was not scheduled.

Later that day, the student testified, Reitz pulled her out of an art class to watch some filmstrips. While alone with Reitz, she said, Reitz kissed her without her consent.

Reitz testified that he met the girl May 10 for a tutoring session because of her failing grades.

Prosecutor Michelle Taylor presented evidence that Reitz had 37 sexually explicit magazines and tapes stored in a closet in his classroom. Reitz said the materials had been confiscated from students, although he admitted he had brought two of the magazines to school to show to colleagues.

Defense attorney Thomas Morrow attacked the student's veracity, saying she fabricated the story after watching the movie "Tribes," about a science teacher and a popular student. "She had the tiger by its tail. She couldn't let go," Morrow said.

The girl's mother reported the sexual abuse to authorities.

Each fourth-degree sex offense carries a one-year prison term. The maximum penalty for child sex abuse is 15 years on each count. Reitz is scheduled to be sentenced Jan. 11.