Its trade parts counters in Hemel Hempstead, High Wycombe and Aylesbury will be supported by a fleet of 50 delivery vans and motorcycles.
A spokeswoman said another three openings were planned for later this year, with the next addition due to begin trading in Watford next month.
The company has its sights on building awareness and sales within the independent aftermarket.
Trade sales account for around 80% of ECP’s business. Originally a specialist in French and German marques, it has expanded in the past two years to encompass all-makes parts supplies. Brands stocked include Bosch, ATE, Sachs, Denso, Valeo and Lucas.
ECP has an annual turnover of £110m.
Last year it bought ARE in the south of England, which has 13 outlets specialising in parts for cars and commercial vehicles.