The Olympic and Paralympic athlete was charged on Friday with the premeditated murder of 29-year-old Reeva Steenkamp, who was shot dead at his luxury Pretoria home.
He had been contracted to compete in races in Australia, Brazil, Britain and the United States between March and May.
"I have decided that following these tragic events that we have no option but to cancel all future races that Oscar Pistorius had been contracted to compete in, to allow Oscar to concentrate on the upcoming legal proceedings," manager Peet van Zyl said.
Sponsors and partners would in the meantime maintain their contractual commitments awaiting the outcome of the legal process, said Van Zyl uin a statement.
Pistorius is accused of killing his girlfriend who was shot four times. Police reportedly found a bloodied cricket bat at the house, according to a local Sunday paper.
Pistorius' family denies he intentionally killed the blonde covergirl. His father said he had "zero doubt" his son had mistaken Steenkamp for an intruder and his 89-year-old grandmother told AFP the killing was accidental.
The family has said the 26-year-old, who is widely seen as an adrenaline junkie with a love for speed and guns, is "numb with shock as well as grief" over Steenkamp's death.