The Leeds-born actor has featured in each of the Harry Potter films alongside Daniel Radcliffe, Emma Watson, Helena Bonham Carter, Ralph Fiennes and Julie Walters.
The Harry Potter series is set to conclude in July 2011, and Multitude Media will work with Lewis to build on his profile around the release of the remaining two films as well as his ongoing career.
Will Wood, Multitude Media founder and director, said: ‘We are delighted to be working with an exciting young acting talent like Matthew as he begins to plan for the next chapter in his career.'
Multitude Media was founded in 2008 and operates across the sport and entertainment sector. With bases in Leeds, London and Manchester, current clients include England and Manchester City footballer Micah Richards, Manchester Comedy Festival and Oscar winning actress Emma Thompson’s theatre company Shatterbox.