MD-88
Air Traffic Control Developmental
Inflight Event / Encounter Other / Unknown
General None Reported / Taken
Company Policy
[Two MD88's were] both at FL280. Air Carrier XXXX was first. A speed was an assigned to trailing Air Carrier XXYX of not to exceed 270 KTS. Air Carrier XXXX read this back. R-Side recognized the overtake of back aircraft and descended it to FL260. Aircraft did not read back so R-Side assigned it again and obtained the read back; similar sounding call signs. Not having company with similar sounding call signs at the same place and same time.
ZMA Controller described a potential loss of separation event claiming similar sounding call signs was the primary causal factor.