Private equity-owned business software company BMC Software Inc has ended talks to merge with enterprise software maker CA Inc after struggling to arrange financing for the deal, a source familiar with the matter said on Thursday. The termination of the negotiations shows that banks are still reluctant to finance leveraged buyouts of mature technology companies at hefty valuations. It follows unsuccessful attempts earlier this year by Citrix Systems Inc , another business software maker, to go private. The source asked not to be identified because the negotiations were confidential. CA and BMC could not immediately be reached for comment.