Reed Elsevier's LexisNexis has struck a deal to acquire Interface Software, a private provider of relationship management services to law firms in the US, UK and Australia, for an undisclosed sum.

The transaction, which involves the US-based legal information provider buying all of Interface's outstanding shares, is expected to be announced today. It marks the latest in a series of small acquisitions made by LexisNexis in its attempt to expand beyond its traditional business of providing research.