Enter a third break to terminate BTEQ. Alternatively, entering either EXIT or QUIT after the first break also terminates BTEQ.
Triple-breaks can be used to end batch more or interactive mode BTEQ execution. However, for BTEQ to recognize a triple-break scenario, the breaks (pressing CTRL+C key) need to happen fairly quickly, or else BTEQ may recognizing them as single breaks. So, pressing and holding down CTRL+C can be used to effectively simulate the triple-break scenario.