Slaughters will use its European best friends to service its deals, including Bredin Prat in France and Bonelli Erede Pappalardo in Italy.
GE took the unusual step of putting together the panel without inviting any firms to pitch. Ben O'Halloran, GE European M&A legal head, said: "Our plan wasn't to issue a general invitation for submissions. We'd been in touch with the various firms so we sat down and looked at the big picture.
"First we made the decision and then asked the firms for submissions as a confirmatory measure."
Despite being on GE's UK panel, Clifford Chance was a surprise omission from the European M&A list. O'Halloran said the firm will continue to receive work from GE, but in practice areas other than M&A.
The firms that did make the roster will enjoy a boost to corporate revenue over the coming years. GE spends "tens of millions of dollars annually" on M&A legal advice in Europe, according to O'Halloran.
The company will not rotate the firms, but will choose the most appropriate adviser for each deal. O'Halloran said GE would monitor the usage of the different firms and investigate if one or more firms were not receiving work.
The panel is the first in a series of European legal reviews for GE as the company seeks to reduce the number of external advisers on its rosters.
"We've done this kind of preferred provider programme in the US and we have programmes in place for the various practice areas," said O'Halloran. "One of the driving forces behind this is [global general counsel] Brackett Denniston. He's keen that we move to a model where we have fewer and deeper law firm relationships."
GE European general counsel Mark Elborne is currently reviewing similar European panels for different practice areas, which are due to be unveiled next year.