(L-R) Linklaters partners Roger Barron and Jessamy Gallagher with Babita Maria, divisional manager UK & Ireland, legal, Intralinks

Finalists: Ashurst; Baker McKenzie; Dechert; Herbert Smith Freehills (highly commended); Norton Rose Fulbright; Skadden Arps Slate Meagher & Flom; Slaughter and May (highly commended).

Linklaters won the M&A Team of the Year (Large Deal) award, sponsored by Intralinks, for its work advising National Grid on the sale of a majority stake in its gas distribution network.

That involved separating its gas distribution business and transferring all of its contracts, assets and liabilities into a newly formed holding company, paving way for the sale of a 61% equity stake of the business to a consortium of international investors and implying an enterprise value for the gas distribution network of about £13.8bn.

One challenge in spinning off its gas network into a separate company and making it attractive to investors was the amount of debt it could hold relative to its assets – it would need to be higher than the energy regulator's limit, while at the same time needing to maintain an investment-grade credit rating so it could benefit from cheaper borrowing costs.

That meant setting up a separate structured financing platform for the new company, which would allow for greater leverage without compromising the company's credit rating – a financing package that has only been used once before for a utility business.

"Biggest UK infrastructure deal in 10 years – so many aspects to this deal make it worthy winner," a judge noted.