* Digital Realty Trust Inc. unit Interxion BV purchased Croatia-based carrier-neutral data center provider Altus IT for an undisclosed amount. * Newly established closed-ended investment company Home REIT PLC plans to raise £250 million in an IPO on the London Stock Exchange. * Sino-Ocean Group Holding Ltd. is planning to spin off and list Sino-Ocean Service Holding Ltd., its property management business, on the Hong Kong stock exchange. The parent company will own at least a 50% stake in Sino-Ocean Service upon the completion of the planned spinoff.