Dell Inc. said Dave Johnson, who handled mergers and acquisitions, has departed to take a senior position at private-equity firm Blackstone Group LP.

Johnson’s responsibilities will be handled by Chris Kleiman, who will be in charge of corporate development, and Prakash Jothee, who will run the corporate strategy team, Round Rock, Texas-based Dell (Nasdaq: DELL) said in a statement.

Both executives will report to Chief Financial Officer Brian Gladden.

Dell hired Johnson from IIBM (NYSE: IBM) in 2009, triggering a lawsuit by IBM seeking to block his employment at Dell because it said he violated a noncompetition agreement. Dell prevailed in the suit, and Johnson went on to accelerate Dell’s deal-making.

On his watch, Dell spent about $10 billion on more than 20 acquisitions, David Frink, a spokesman, said in the statement.

Dell oversaw the 2009 purchase of Perot Systems to put Dell into technology services competition with IBM and HP, Reuters noted in its report.

Shannon Cross, an analyst with Cross Research, told Reuters that Johnson had put in place at Dell an infrastructure for identifying acquisition targets then integrated the acquired companies.

“Dell has successfully used Johnson’s team to expand its IP and product portfolio,” Reuters quoted her as saying.

To diversify beyond its roots as a personal-computer supplier, Dell has been snapping up companies including Quest Software in data-center management, Force10 Networks in computer networking and Compellent Technologies in storage.

The company had $14.2 billion in cash and investments at the end of the fiscal third quarter, Dell said in November.

At the company’s DellWorld conference in Austin, Texas, last month, Chief Executive Officer and founder Michael Dell said the company has spent more than $12.7 billion on 18 acquisitions since 2009, and will focus on small and medium-size deals to add tools that complement its PCs and servers.

(Bloomberg contributed to this report.)