The York-based group agreed to buy Halifax Estate Agencies (HEA) from Lloyds Banking Group for a token 1 in October.
The deal makes LSL, which also owns the Your Move, Reeds Rains and Intercounty brands, the UK's second biggest player in the sector.
The group now has 584 outlets. LSL won 98.9 per cent backing for the acquisition from shareholders last month.
LSL was formed after the management buyout of Your Move, which has around 300 branches, from Norwich Union in July 2004.