The agency was awarded the business, which it claims will have a budget of around £8 million, after completing some work on a project basis for the brand. The account was previously held by Interfocus.
MPGM will now spearhead a campaign to launch three new Pulsar collections - Poise, Prestige and Performance. The campaign will break later this month.
The print campaign will showcase the brand's design, engineering and quality, introducing the strapline: "Pulsar. The difference is in the detail."
The Seiko account remains with Interfocus.
Andrew Mitchell, a managing partner at MPGM, said: "We have an international brand positioning and a campaign that can focus on Pulsar's true 'innovation and attention to detail'."