The Birmingham based print manager and marketing services specialist was set up by former St Ives director Simon Ward in 2009.
Bridgepoint previously backed the MBO of SP Group when Ward was a director at the point-of-sale specialist, prior to its purchase by St Ives ten years ago.
ITG was previously backed by Isis Equity Partners, which invested £3.2m in the business in 2010 when ITG acquired Total Marketing Services, developer of the cloud-based Media Centre platform around which ITG has built its business.
Fast-growing ITG had sales of £43.2m in the year to 31 August 2013, said Bridgepoint, a jump of 32% on the prior year.
With the new backing ITG is now poised to expand its offering into Europe and North America.
Bridgepoint partner Adrian Willetts said he believed the business could double in size in five years.
Ward, ITG’s chief executive, said: “We look forward to working with BDC to deliver our plans for further growth, both within the UK as well as internationally where we have recently had new business success.”
Isis partner Pete Clarke described ITG as a "fabulous business", and added: “We have enjoyed every minute of working with Simon and the team and wish them well in the next phase of the development of the business – long may their success continue.”