PUEBLO, Colo. (AP) _ Kelly Reno, 18, who played the boy marooned with a beautiful horse in the 1979 film, ''The Black Stallion,'' sustained a broken leg and possible internal injuries in a car accident today, a hospital spokeswoman said.

Reno, of Pueblo, was involved in an auto accident along with 15-year-old Lynette Tuttle of Pueblo, said Cherry Trimble, nursing supervisor for St. Mary Corwin Hospital.

Reno's mother, Ruth Reno, who lives south of Pueblo, confirmed that her son starred in the Francis Ford Coppola film, and told the Colorado State Patrol that her son said he was driving at the time of the accident.

Ms. Trimble said Reno, who was listed in serious condition, sustained a broken leg, a collapsed lung and possible kidney injuries. Ms. Tuttle was being treated for a broken ankle, bruises and scrapes, Ms. Trimble said.

Patrolman Al Hecht of the State Patrol said a preliminary investigation indicated that Reno's pickup truck was northbound on Interstate 25, attempting to pass two semi trucks, at the time of the accident.

Tire marks indicated that Reno's truck veered to the left, colliding with the front semi truck, Hecht said.

''He lost control, skidded into the median, rolled 21/2 times and both occupants in the truck were thrown out,'' Hecht said.

No cause of the accident was determined, and no fault assigned, he said.

''We're still trying to piece it all together - we're still trying to figure out why,'' Hecht said.