Dixons and Carphone Warehouse will reveal the terms of their £4bn merger this week which they say will create hundreds of jobs.
The potential deal was officially announced on 20 February but its deadline has been extended by eight weeks.
The deal, which will involve Carphone effectively taking over Dixons, is thought to give both companies more access to the fledgling Internet of Things market.
It is understood that store closures will be kept to a minimum.
“Dixons is under-exposed to the key area of mobile/smartphone retailing and it is known to have been looking at getting more involved in that area,” said retail analyst Nick Bubb.
Dixons employs 31,000 staff across 530 UK stores while Carphone operates 867 UK stores.
The deal brings together two of Britain’s most successful retailing entrepreneurs; Dixons was founded in 1937 by Charles Kalms and Michael Mindel in Southend with £100 while Charles Dunstone and Julian Brownlie founded Carphone Warehouse from a rented flat on the Marylebone Road in London with £6,000 in 1989.