"We are transforming Power Grids, we are running on all cylinders to drive this transformation, we have really solid top-line growth, we are now at the margin corridor," Spiesshofer told reporters on a conference call after results on Thursday.

"But we are just at the margin corridor, so there is more homework to be done."

When asked if this meant the business would stay with ABB or be sold, Spiesshofer said: "When the time is right to talk more about it, we will talk about that."

(Reporting by John Revill; Editing by Michael Shields)