No concerns were raised during the due diligence stage, but Aegis is said to have then tabled a revised offer, about a third less than the original sum, blaming the economic outlook for lowering its bid.
The offer was rejected, as was a subsequent Aegis offer this week that, though reconfigured, was still below the original sum on the table.
Aegis is one of a handful of suitors to emerge since ILG hired investment banking advisors to undertake a strategic review of the business.
As well as Aegis, ILG has been in talks with the digital network AKQA and a number of private equity groups.
The impending change to the Capital Gains Tax rules in April is understood to have spurred talks and provided a target deadline for a deal.
Andrew Walmsley, the founder of i-level, retains a substantial shareholding in the business, as do a range of current and ex-employees.