London - Leading global law firm Mayer Brown advised London-based Ecofin Energy Resources PLC (Ecofin) on its merger with ASX listed Amadeus Energy Limited to create a leading ASX listed mid-cap oil & gas company worth US $200 million.

Subject to approval by Amadeus shareholders, the combination will create an oil and gas company with a portfolio of US onshore conventional and unconventional assets, including material exposure to the Eagle Ford and Barnett Shales in Texas, as well as acreage prospective for the Bakken / Three Forks formations in the Williston Basin, Montana.

The Mayer Brown team advised on the UK and US aspects of the transaction and Herbert Smith Freehills advised on the Australian aspects of the transaction. The Mayer Brown team was led by London Corporate & Securities partner Robert Hamill assisted by Tax partner James Hill, Employment & Benefits partner Andrew Stanger, Tax partner Jim Barry (Chicago), Corporate & Securities senior associate Rebecca Bothamley and Employment & Benefits associate Ryan Liebl (Chicago).

Robert Hamill, Corporate & Securities partner, said: "This is an exciting merger for Ecofin, bringing together two complimentary businesses in the fast developing US onshore shale oil and gas business."

The deal is one of many projects that Mayer Brown has completed in the oil and gas sector this year, with the firm recently advising Canaccord Genuity in its role on the largest floatation on an oil and gas company on AIM in the last five years for Eland Oil & Gas PLC. Mayer Brown was ranked 7th by value in the Thomson Reuters M&A league tables published in September.