Slaughter and May, Lovells and Berwin Leighton acted on a deal that lawyers claim lays the foundations of a new legal technique for selling commercial property.
Shell sold 180 of its busiest filling stations to private company London & Regional Properties (LRP) in a unique £300m sale-and-leaseback transaction.
Slaughters and Berwin Leighton advised Shell while Lovells represented LRP and its funder, Credit Suisse First Boston.
Lawyers involved claim this is the most flexible business-oriented property contract that has ever been drawn up in a sale-and-leaseback deal.
It is the first to allow the seller to remove, assign to other parties or add properties to the contract if its requirements change. In the past contracts have given the seller far fewer rights over its leased-back properties.
Robert Kidby, head of property at Lovells, says: "More businesses are bound to follow suit."
Katherine Watts, a Lovells property assistant who worked on the deal, says: "This could be a blueprint for banks and retailers who own an awful lot of their own stores but are not getting the best value."
Lovells hopes to have gained LRP as a new client after the deal, which it describes as "complex". Credit Suisse was already a client and introduced the firm to LRP.
Slaughters pushed through the more complex legal issues of the deal for Shell, such as the intricate wording of the contract, and Berwin Leighton handled work including property title investigations.
David Taylor, head of property at Berwin Leighton, says: "We did a good job for them. I have every reason to hope that Shell will use us again."