The Wakefield-based sportswear firm has manufactured team kits and training wear for 100 years. It has charged Ptarmigan with increasing its brand awareness in football.
It will also be supporting the company's expansion into other sports including rugby league, rugby union, hockey and netball.
Prostar manufactures kits for Shrewsbury Town and Chester City football clubs.
Ptarmigan replaces incumbent agency Green Communications. The agency won the account without a competitive pitch.
'We're really eager to raise our profile across a number of key sports and left everyone know about the quality products we have on offer,' said Prostar sales and marketing director Shane Bray.