SMA X HAD LTSS FROM LTT SAME ALT ASSIGNED. SYS ERROR. EVASIVE ACTION TAKEN.

Narrative

CTLR 'A' WORKING A SECTOR SE OF MINE; RADAR IDENTED A VFR SMA X AT 9500 FT. THE SMA X WAS LNDG IN MY AREA SO I TOOK RADAR HDOF. CTLR 'A' THEN CALLED AND SAID THE SMA X WAS NOW IFR DSNDING TO 3000 FT ON A 320 DEG HDG. I APPROVED. ACFT CAME OVER TO MY FREQ. ACFT TRANSITIONED THROUGH CTLR 'B' AIRSPACE. MY ACFT DSNDING OUT OF 6000 FT NOW STILL ON 320 DEG HDG. CTLR 'B' ACFT; AN LTT JET; AT 6000 FT; SBOUND; DSNDING ON CONVERGENT COURSE WITH MY SMA X. I CALL AND ALERT CTLR 'B' TO SIT. BOTH ACFT AT 5000 FT NOW DSNDING; CONVERGING; 5 MI APART. LTT IS DSNDING FASTER THAN SMA X SO I CLB SMA X FROM 4700 FT BACK TO 5000 FT. LTT IS BELOW SMA X BUT THEN ALSO BEGINS TO CLB (CTLR 'B' HAD SAME IDEA AS ME AND CLBED LTT BACK TO 5000 FT). TARGETS PASS; LTT IS BELOW; MINIMUM SEPARATION IS 200 FT; 1/2 MI. MY SMA X DOES NOT SEE LTT UNTIL MOMENT THEY PASS. CAUSE OF PROB: EITHER CTLR 'A' DID NOT POINT OUT SMA X TO CTLR 'B' OR CTLR 'A' DID POINT OUT AND CTLR 'B' APPROVED WITHOUT REALLY UNDERSTANDING SIT. CONTRIBUTING FACTOR: SMA X WAS LEFT ON A VFR BEACON CODE AFTER HAVING BEEN GIVEN IFR CLRNC. IF SMA X WAS ON IFR CODE; CTLR 'B' MIGHT HAVE BEEN MORE AWARE OF AND ATTENTIVE TO SMA X. CTLR 'B' AND I WERE UNAWARE OF EACH OTHER'S INTENTIONS. WE BOTH STOPPED OUR DSNDING ACFT AND BOTH CLBED TO 5000 FT. WHEN I CALLED AND BROUGHT SIT TO CTLR 'B'S' ATTN I DID NOT ASK HIS INTENTIONS OR TELL HIM MINE -- IF WE KNEW WHAT KIND OF ACTION ONE OF US WAS PLANNING TO TAKE; SIT MAY HAVE BEEN AVOIDED.