Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Situational Awareness
ATC Issue All Types; Conflict Ground Conflict; Critical
Air Traffic Control Issued New Clearance; Flight Crew Rejected Takeoff; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Human Factors; Procedure
ATC cleared us for takeoff; and prior to 80 knots; on the takeoff roll; they cancelled our takeoff clearance. As we were coming to a stop; we had to ask them what they wanted us to do. We were told to clear the runway. We went through our procedures and checklists to prepare for another takeoff. I queried ATC as to what the reason was for the canceled takeoff; and the Tower told us '[another aircraft] was on top of us and he thought it would be safer to keep us on the ground.' We got no further communication from ATC about the incident and took off without any further issue.
B737 Captain reported ATC cancelled their takeoff clearance after they had begun takeoff roll due to another aircraft overflying them.