In terms of electrical machines, stepper and BLDC motors are both PMSM (permanent magnet synchronous motors respectively machines). This involves several common properties. The usual control methods are however different, also the preferred number of phases and pole pairs.
We still don't know for sure what the OP means with three wires BLDC. He may refer to a three phase motor, or a motor with built-in electronics and an additional control or monitor cable.