Eversheds has handled its largest ever single deal with 40 of its lawyers advising US chemical giant DuPont on its £1.8bn purchase of three chemicals divisions from ICI.
The firm became DuPont's primary UK legal adviser a year ago when, as part of a programme to streamline its legal advice worldwide, the chemicals company held a UK beauty parade which included the then Dibb Lupton Broomhead and another unnamed City firm.
ICI is selling its titanium dioxide, polyester and polyester film operations to raise money for its already-agreed £4.9bn acquisition of Unilever's speciality chemicals division, trans-forming itself from a bulk industrial chemicals group into a leader in specialised chemicals.
Freshfields advised ICI on the Unilever purchases, but for the sell-off to DuPont the company has used two other City firms, Allen & Overy and Linklaters & Paines.
Michael Herlihy, ICI's head of legal, said: "I am sure Freshfields could have supplied more people to do this deal, but they would not have been people that we knew."
He brought in Allen & Overy to advise on the polyester and polyester film businesses because one of its partners, Ian Elder, was a former in-house lawyer at ICI who had worked closely with those businesses.
Linklaters, which had already advised ICI on the massive Zeneca demerger, had been instructed in February to prepare Tioxide, the titanium dioxide business, for flotation.
Herlihy said that when DuPont's offer to buy Tioxide and the other businesses materialised in mid-May, "we had a very open discussion about whether we should transfer all the work from Linklaters to Allen & Overy".
But because Linklaters was already heavily involved and ICI and DuPont wanted the deal done within seven weeks before news leaked out, both firms were retained.
Corporate partner Donald Williams led the Linklaters team. Gary McClean played a lead role with Elder for Allen & Overy and ICI staffer Wynne Turner assembled an in-house team of between 12 and 15 lawyers from the US and the UK.
DuPont's in-house team, led by Mireille Quirina, chief counsel for Europe, set up camp at Eversheds' London office together with the Eversheds team, led by corporate partners Martin Issitt and Paul Scrivener. They spent two weeks doing due diligence.
The day before signing was due, to coincide with the opening of the New York stock exchange, The Sunday Times revealed the deal and lawyers had to work through the night to bring forward the signing so it fell before the opening of the London Stock Exchange that day. Both companies believe obtaining regulatory approval will take about six months.
Unions representing ICI workers have objected to the sale claiming that the last time ICI businesses were sold to DuPont, the US company sacked hundreds of staff despite promising no redundancies.