Nabarro Nathanson is advising the Post Office in its first major deal since it was freed from commercial shackles by the Government's White Paper on its reform in July.
The Post Office is making a joint bid for the lottery contract with current operator Camelot, which is advised by Cameron McKenna.
Nabarro Nathanson corporate partner Robert Tudway says: "This is the first time in the UK that the Post Office has been able to use the increased commercial freedom which it has recently been granted."
Joanne Winship and Caspar Branson were the Post Office's in-house lawyers, and Nabarro Nathanson's corporate partners Tudway and Gareth Jones, and competition partner Cyrus Mehta worked with back-up.
The Post Office appointed Cameron McKenna and Slaughter and May to their panel of law firms for commercial work. But by that time, Nabarro Nathanson's had started work on the bid.
The regulator is expected to come to its decision mid-2000 on who will operate the lottery from 2001 when the current licence expires.