SAN LEANDRO — A motorcyclist was killed after losing control while splitting lanes on southbound Interstate 880 this morning, authorities said.

The victim, a 45-year-old Alameda man, was not being named until his next of kin are notified.

The two left lanes of southbound I-880 were closed north of Davis Street from 7:30 to 9:15 a.m., backing up traffic and causing 40-minute delays. A Sig-alert was issued and big rigs were diverted to I-580.

At 7:27 a.m., traffic was moving about 40 to 50 miles per hour when the motorcyclist — traveling about 70 to 85 miles per hour on a blue BMW motorcycle — drove between the two fast lanes north of the Davis Street exit, California Highway Patrol Officer Cristina Tagle said.

He apparently clipped a white 24-foot box truck in the No. 2 lane and then struck a black Volvo in the No. 1 lane, Tagle said.

He lost control, may have been thrown from his motorcycle, and later was pronounced dead at the scene. He didn't appear to be run over, Tagle said.

The truck, the Volvo and a witness stopped and assisted with the investigation.