HAMPDEN – Three R.H. Foster convenience stores connected with the company’s ExxonMobil stations will be converted to the On the Run franchise by year’s end, company President Robert W. Foster said Wednesday.

The Mobil Mart in Ellsworth is changing over, as are the One Stop stores in Machias and Milford.

“We’ll push hard in this next week to do this, but we’ll get them done,” Foster said.

All of R.H. Foster’s 17 stores in Maine will be converted to On the Run in the next couple of years, he added.

Two are already On the Run stores: the Airport site on Union Street in Bangor and at Snow’s Corner in Orrington.

On the Run is a franchise of convenience stores owned by ExxonMobil Corp. There are more than 600 On the Run franchises across the country, according to the National Association of Convenience Stores.

R.H. Foster sold 49 percent ownership in its gas stations to ExxonMobil in 1999.

By switching over to On the Run franchises, Foster said, “it will bring us benefits, better buying power and marketing, better specials and promotions.”

For the ordinary customer, the company believes, the change means better brand awareness.

R.H. Foster Energy LLC, now based in Hampden, was founded in 1961 by Robert H. Foster.