A historic peak in global mergers and acquisitions (M&A) in the first half of 2018 has seen the energy and power sector retain its lead as the biggest contributor, with the value of deals increasing by 62%, Thomson Reuters data showed.

The value of energy and power transactions announced globally rose to $365.7bn in the first six months of the year from $225.5bn a year earlier and accounted for almost 16% of total M&A value. Utility companies in mature markets have been undergoing a wave of consolidation, looking to create scale partly because of the increasing shift to renewable energy sources that is forcing them to change business models.

Among the most high-profile deals, Germany’s top utilities RWE and E.ON agreed to break up RWE’s subsidiary Innogy and divide its assets between them in a €5.2bn deal, while China Three Gorges launched a $10.8bn bid to take control of EDP, Portugal’s biggest company.

As confidence picked up after crude oil prices climbed above $70 a barrel in January for the first time in three years, a wave of consolidation has also been seen in the downstream segment of the oil and gas sector.

Marathon Petroleum agreed to buy rival Andeavor for more than $23bn, creating one of the largest global refiners that will benefit from access to booming US shale.