The group, which offers administrative services for companies setting up branches and entities in various jurisdictions, blamed a decline in the Netherlands, Luxembourg and the Cayman Islands over the fourth quarter.

"This was mainly due to lower productivity as a result of elevated employee attrition, which continued through the end of December," Intertrust said in a pre-released earnings update.

The group's underlying revenue growth came in at around 1.5% for the full year, against an initial estimate of 2% to 4%.

Its adjusted earnings before interest and taxes and amortisation (EBITA) margin reached about 30%, slightly below guidance of 31% to 32%.

Intertrust confirmed the around 1.8 billion euro ($2.06 billion) public offer for the firm by U.S.-based corporate services firm CSC was progressing as planned.

In November, it said it had received multiple expressions of interest from third parties, having earlier announced exclusive discussions with British private equity firm CVC Capital Partners.

CVC Capital pulled out of those talks in December.

Intertrust is scheduled to announce fourth-quarter and full-year results on February 10.

($1 = 0.8740 euros)

(Reporting by Juliette Portala; editing by Clarence Fernandez and Jason Neely)