The Competitions and Markets Authority has opened an investigation into the proposed merger of SSE Retail and Npower.
In what is a widely expected move, the CMA is to assess whether or not the deal - first proposed late last year - has the potential to reduce competition within the UK energy supply market.
In a statement issued today the CMA said it had been in open discussions with both SSE Retail and Npower since the deal was first announced and it now had sufficient information to start its review.
That investigation will assess the proposals on competition grounds. A deadline for the initial decision has been set for 26 April 2018.
Interested parties however have until 14 March 2018 to provide comment.
Earlier today SSE and Npower parent company innogy formally confirmed their intention to merge and Alistair Phillips-Davies chief executive at SSE, said the parties would “continue to work constructively” with the CMA and other interested parties.
“The scale and pace of change in the GB energy market continues to be significant and requires us to evolve to stay relevant, competitive and sustainable. We remain confident that the creation of a new, combined, standalone Retail business will best serve the needs of customers, employees and shareholders in the long term,” he said.