The scheme, which was trialled with 38 of its symbol and independent retailers in the Midlands from last August, offers advice on category management and merchandising as well as exclusive promotional packages for big brand products.
Retailers will also be entitled to claim back 2.5% of their spend with the company on a quarterly basis. The payout will be subject to a minimum spend, worked out on a store-by-store basis, and excludes tobacco.
Stores will be split into three categories in their membership - c-store, CTN and forecourt. A series of 10 regional meetings will start this week to explain the scheme in detail.
P&H chief executive Chris Etherington said: "Through Partnership Plus, P&H will leverage its scale and understanding of the retail sector to provide a fully integrated offering."