BM Regional yesterday announced that it will strengthen it's partnership with SN by operating additional flights within Europe on behalf of SN and by entering into a full codeshare agreement in there BRU-EMA route.
bmi regional strengthens partnership with Brussels Airlines | bmi regional airlines
From the 7th December 2015 BM's flights between EMA and BRU will be retimed with ER4 replacing the current ER3 on the route. It also appears the aircraft will be based in BRU.
From 7th December
BM1233 EMA 07:30 BRU 09:40 ER4 x567
BM1237 EMA 19:35 BRU 21:45 ER4 x6
BM1234 BRU 06:55 EMA 07:05 ER4 x567
BM1238 BRU 18:55 EMA 09:05 ER4 x6
On the same day BM will begin operating flights from BRU to SXB on behalf of SN. BM will also begin operating flights to NUE on behalf of SN from February 2016.