A federal judge in San Francisco has declined to delay the Jan. 17 execution of the oldest man on California's death row, who says he is so ill that he has been unable to assist his attorneys in preparing a clemency petition.

Clarence Ray Allen, 75, was sentenced to death in 1982 for commissioning the murder of three people in Fresno. If the sentence is carried out as scheduled, Allen would become the oldest person executed in California since the death penalty was reinstated in 1978.

Allen is legally blind, has heart ailments and diabetes, and uses a wheelchair. His attorneys assert that top officials in the California Department of Corrections and Rehabilitation and at San Quentin State Prison have provided inadequate medical care to Allen. They also say that the state violated Allen's rights to counsel, to due process and to be free from cruel and unusual punishment.