The two businesses include 32 repair locations, £90m turnover and 700 staff.
The double acquisition continues Steer Group's aggressive strategy of growth through acquisition and extends its presence in the south of England.
Apollo Motor Group has 20 sites located across the Southeast and South West of England. Led by the current management team of Paul Clements, Chris Dore, Bradley Eyles and Mark Fletcher, the business has a strong reputation nationally for the quality of its operations and in particular its focus on its staff and Academy for which they have won numerous awards.
Balgores Motors was founded in 1982 and has grown into 12 sites with a heavy bias towards prestige vehicle manufacturer approvals. Led by Gary Dench, Steve Austin and Andy Pennell, the company has a reputation for the technical quality of its repair operations and the culture of the workforce, many of whom have achieved long service awards.
Richard Steer, chief executive, said: "We have a clear focus on acquiring strong well-established businesses that support our growth strategy and when the opportunity presented itself, we jumped at the chance to add Apollo and Balgores to our operations. We are very excited about the prospects and look forward to working with the incumbent management teams on the journey ahead."