Osprey Group said Monday morning that it has completed “a major refinancing” agreement with the London-based private equity firm Alcuin Capital Partners. The funding, Osprey said, will be used to finance additional acquisitions. Best known for its military history publishing program in the U.K. and U.S., Osprey has been expanding into other niche markets.

“Since acquiring Shire in 2007 we’ve been engaged in a process of growth and development that has included the acquisition of Angry Robot in 2010 and that of Old House Books & Maps in April 2011. We have successfully managed to grow Shire at 50% year-on-year in 2010 as well as launching Angry Robot into the USA within three months of acquiring it. We have a clear focus on creating content for niche enthusiast markets and welcome the flexibility and reach that Alcuin’s investment gives us,” said Osprey managing director Rebecca Smart in a statement. Osprey is “actively seeking acquisition targets” that serve enthusiast niches, the company noted.

Following the completion of the transaction, Alcuin holds the controlling interest in Osprey, while the company’s existing majority shareholder, Botts Capital Nominees Limited, will remain a significant minority shareholder