* Banerjee only joined ABB in mid 2012
* Follows Friday's news Hogan to stand down as CEO
* Claes Rytoft named acting CTO (Rewrites first paragraph, adds detail and background, analyst comment)
By Caroline Copley
ZURICH, May 13 Swiss engineering group ABB Ltd has announced a second senior executive departure in less than a week, saying its chief technology officer (CTO) was quitting just three days after revealing its chief executive was to leave.
The world's biggest supplier of industrial motors and power grids said Prith Banerjee, who joined ABB in 2012, would leave for family reasons in the next few weeks after less than a year in the post.
It said Banerjee would return to the United States where he would take up a position outside the group and added that a successor would be named in due course.
ABB said it was looking internally and externally for candidates and named Claes Rytoft, head of technology at the group's power division, as acting chief technology officer.
Banerjee's departure comes after Friday's surprise announcement that Chief Executive Joe Hogan would be standing down for unspecified private reasons. ABB also changed its chief financial officer just three months ago.
"From a timing point of view, it's of course less than perfect to see the CEO departing and one (working) day later find out the CTO is going too," said Helvea analyst Stefan Gachter. "But he has been at ABB for one year so not much know-how is leaving the company."
A spokesman for ABB said the timing of the announcement was pure coincidence and that Banerjee was leaving to be closer to his family in the United States.
Banerjee had joined ABB from Hewlett Packard Co and was formerly a professor of electrical engineering at the University of Illinois.
As when it announced Hogan's exit, ABB did not say if Banerjee would be getting a payoff.
The group in April warned it faced a tough second half of the year and said it was stepping up cost-saving measures. Its shares, which had risen in February to a 19-month high of 21.90 Swiss francs, were down 0.8 percent at 21.34 francs by 0941 GMT.
"Prith has brought new momentum to ABB's research and development activity," said Hogan in a statement. "I regret Prith's decision to leave the company. I'd like to thank him for his contribution and wish him all the best for the future." (Editing by David Holmes)