* IPO of 7 mln common units priced at $20/unit

* Barclays Capital, Citigroup and Deutsche Bank Securities joint book-running managers for IPO (Follows alerts)

Dec 8 (Reuters) – Rose Rock Midstream LP (RRMS.N), a limited partnership formed by SemGroup Corp (SEMG.N), priced its initial public offering at $20 per unit, the mid-point of its expected range.

Rose Rock, which was formed by SemGroup to own, operate, develop and acquire a diversified portfolio of midstream energy assets, sold 7 million common units in the offering, raising $140 million in proceeds.

Barclays Capital, Citigroup and Deutsche Bank Securities are joint book-running managers for the IPO.

via UPDATE 1-Rose Rock Midstream prices IPO at midpoint of range | Reuters.