OPPOSITE DIRECTION ACFT TFC IN NMAC.

Narrative

APCH HAD JUST CLRED US FROM 8000 FT TO 7000 FT AND CALLED 12 O'CLOCK TFC. I SPOTTED TFC AT 12 O'CLOCK HIGHER AND POINTED IT OUT TO THE FO. THE FO ASKED ATC IF OUR TFC WAS '12 O'CLOCK HIGHER; ABOUT 8000 FT.' ATC SAID; 'NEGATIVE; YOUR TFC IS SUPPOSED TO BE 12 O'CLOCK AND 6000 FT.' THE FO SAID TO ATC; 'WE SEE TFC AT 12 O'CLOCK AND AT OUR SAME ALT COMING RIGHT AT US!' THE FO WAS REFERRING TO THE SAME TARGET WE FIRST THOUGHT WAS HIGHER; IT SEEMED TO BE DSNDING RIGHT TOWARDS US AS WE WERE LEVELING AT 7000 FT. THE FO STARTED FLASHING 1 OF OUR LNDG LIGHTS TO TRY AND GET THE OTHER AIRPLANE PLT'S ATTN. ATC CAME BACK AND SAID; 'TURN R; NOW; TO HDG 050.' BEFORE ATC COULD FINISH THIS STATEMENT I HAD TO DISENGAGE OUR AUTOPLT AND TAKE AN IMMEDIATE R DIVING TURN TO AVOID A MIDAIR COLLISION. THE TFC PASSED JUST ABOVE AND TO THE L OF US. ONCE CLR OF THE TFC; I IMMEDIATELY CORRECTED OUR COURSE AND ALT; AND THE FO ADVISED ATC OF OUR EMER DEV. I SINCERELY BELIEVE IF I HADN'T REACTED WHEN I DID WE WOULD HAVE HAD A MIDAIR COLLISION. ONCE ON THE GND; SEVERAL OF OUR PAX STOPPED BY THE COCKPIT AND TOLD US THEY HAD SEEN THE OTHER ACFT PASS BY THE L SIDE VERY CLOSE.