Dell Inc. unveiled plans Tuesday to acquire e-mail continuity provider MessageOne Inc. for nearly $155 million in cash to bolster its software as a service offerings.

Dell CEO Michael Dell's brother, Adam, co-founded the Austin, Texas, target. The sale likely provides a solid return for the startup's venture backers.

The company raised several rounds of funding totaling $29 million as of 2006. The latest announced round was $11.25 million in May 2004. New investor QuestMark Partners LP led the funding, which included backers RRE Ventures LLC, Impact Venture Partners and StarVest Partners. Adam Dell is managing general partner of Impact Ventures, while Michael Dell is an investor.

Accordingly, the companies said in a statement announcing the deal Tuesday that they undertook several measures to promote transparency. Michael Dell was excluded from negotiations, and the board took a fairness opinion from Morgan Stanley.

Adam Dell will receive $970,000 in the deal from Impact Ventures, the statement said, while Michael Dell, his wife, Susan, and their children's trust will receive $12 million.

MessageOne provides e-mail services aimed at eliminating the downtime and complexity of the medium with managing, archiving, and long-term storage of e-mail.

Dell plans to offer MessageOne to direct customers and its channel partners.

"MessageOne's offerings add key capabilities to our growing SaaS-enabled services portfolio for the most critical application to businesses of any size: e-mail," Steve Schuckenbrock, the president and chief information officer of Dell Global Services, said in the statement.

This is the third M&A deal for Dell as of late. In November, the company said it would pay $1.4 billion for storage software maker EqualLogic Inc. of Nashua, N.H.

The deal, which stands as the biggest in the Round Rock, Texas-based PC titan's history, was seen as an aggressive push by Dell to ground the company more firmly in software and services.

In August, Dell unveiled plans for a $340 million deal for licensing service provider ASAP Software Inc. from Corporate Express Inc., the U.S. division of Dutch office supplies giant Buhrmann NV.

Dell shares closed up 2.47% Monday at $19.93.