CoreSite Realty Corp, a Carlyle-backed data center REIT with 11 facilities serving over 600 customers, raised $270 million on Wednesday by offering 16.9 million shares at the midpoint of the $15 to $17 range. CoreSite is expected to begin trading Thursday on the NYSE under the symbol COR. Citi, BofA Merrill Lynch, and RBC Capital Markets acted as lead managers on the deal.