Pinsent Masons has tied up its first deal since announcing its merger earlier this month, advising on the £478m sale of medical equipment suppliers Medex to FTSE 100 company Smiths Group.

The newly-forged firm acted for the California-based company on the European aspects of the deal, which closed last week.

Corporate partner Mike McGrath led the Pinsent Masons team with support from solicitor Alistair Cree and competition associate Angelo Basu and assistant Chris Gibson.

Medex is a long-standing Pinsents client, for which the firm has completed work on employment, corporate and property issues.

Hoffman Liebs, one of the firm's European alliance partners, acted for Medex in Germany, while Chicago's Winston & Strawn advised on US aspects.

McGrath said: "We have been working closely with Medex for some time on a number of fronts and we are obviously delighted to have been asked by the company to advise it on a deal of this significance.

"This deal offers Medex considerable opportunities to take its products more widely into world markets," he added.

Pinsent Masons is not, however, a named adviser to Smiths Group and this deal could mark the end of its relationship with Medex.

Freshfields Bruckhaus Deringer, led by London-based competition partner Nicholas French, and Philadelphia firm Morgan Lewis & Bockius represented Smiths Group.

The deal is significant for Freshfields, which has traditionally acted as a secondary adviser to the company behind Allen & Overy.

Smiths Group primarily focuses on the aerospace and defence sector, but is keen to beef up its presence in the medical sector and will pay £322m for Medex, which specialises in catheters and intensive care equipment.

The company will also take on more than £150m of debt as part of the deal, which will boost annual sales of Smiths Group's medical arm by approximately 35%.

The deal, completed last week, brings Smiths Group's acquisitions outlay to £770m so far this year.