SLI co-founder and chief executive Shaun Ryan said the company was looking at "growth opportunities" and Morgan's investment fit with that vision.
"New regions for SLI, such as South America and Asia, as well as our existing markets offer exciting possibilities.
"We are continuing to grow our company in a dynamic and expanding global marketplace, and this opportunity is something that Sam has identified."
SLI's international clients include Harrods, B&Q and Interflora in the UK, and Jelly Belly and Hardrock Cafe in the US.
Its local clients include Mitre 10 and The Warehouse.
The company said it had averaged close to 30 per cent revenue growth year-on-year for the past five years.
It has offices in the USA, UK and Australia and over 100 staff, half of which are based in Christchurch.
Last year, Morgan was part of a group which unsuccessfully attempted to raise $US400 million to build an undersea cable between Sydney, Auckland.