Middle-market lender Solar Capital Ltd. (Nasdaq: SLRC) has purchased Crystal Financial LLC.

Crystal, headquartered in Boston, will continue to operate as an independent finance company. The company underwrites secured debt across a variety of industries. The company has closed and managed more than $20 billion in secured debt commitments.

New York-based Solar is an investment company that focuses on investing in companies through senior-secured loans, mezzanine loans and equity securities. Terms of the deal weren’t disclosed. The transaction closed on Dec. 28.

"This transition was the culmination of a formal process and from inception the Solar team expressed a strong interest in acquiring Crystal given our demonstrated track record as an originator and manager of secured debt investments," Crystal said in a company statement.