It has also made a tender offer to existing shareholders pledging to increase its overall investment in the print and facilities management company to 54m.
3i first invested in Williams Lea in 1965, and values its current 12% stake in the company at around 13m.
The combination of its customer base, market growth potential and service focus of the business make Williams Lea a highly attractive investment opportunity, said 3i London director Steven Nicholls.
It is not clear at this stage where the investment money will be going.
By working with the board Nicholls said the two parties had found a means to provide capital for future growth of the business, whilst allowing some external shareholders to realise some value in the unlisted business.
A new chairman will also be appointed by Williams Lea to support its management team in the next phase of growth.
It is unclear what role the current chairman John Padovan, who took up the role in 2000, will take in the reshuffle.
Despite the investment 3i will continue to remain a minority shareholder in Williams Lea.
The injection of capital follows several major contract wins for Williams Lea, including a 150m five-year print procurement contract with financial services provider, Abbey (PrintWeek 12 February).
by Andy Scott
Have your say in the Printweek Poll
Related stories
Latest comments
"Sorry to read this, a big name to go down, hopefully a lot of the £1.8M was insured. We are recruiting operational staff & currently in-talks to assist the clients with immediate requirements."
"£1.8m !! Very big numbers indeed."
"Now black really is white. Ditching a product line with all its consequences for customers is now an award winning move. Priceless!"
Up next...
News comes a year after the Coronation
King and Queen update Royal Warrants
66-year-old firm closes
DCW Penrose shuttered; kit sold at auction
Finishing from start to finish
IFS lauds partners' premieres and Drupa importance
Government emphasised RM's importance to society