The departure means Bessant is no longer working for parent company Bisnode, the Swedish media group formerly called Bonnier, which he initially joined seven years ago.
His departure was announced suddenly last week in a short statement saying he had left "in order to pursue other interests". The Bisnode board expressed its thanks and wished for his success in the future.
Prospect Swetenhams and Market Monitor are being temporarily led by Alistair Pauline, the business unit manager of Bisnode's credit and risk management division, alongside the remaining senior managers.
Pauline offered no comment about Bessant's resignation and would say only that a replacement would be appointed "soon". It is not known whether Bessant has another job to go to.
In a group level reorganisation in February, Bisnode shifted from a regional structure to a more centralised structure across five Europe-wide divisions. Prospect Swetenhams and Market Monitor moved into the CRM and direct marketing division under business unit manager Geir Feltstykket.
Bessant originally joined Bisnode as managing director of marketing information company Key Note, taking charge of data sales house The Prospect Shop in 2003.
He oversaw the merger of The Prospect Shop with Swetenhams Marketing Services following Bisnode's acquisition of the latter in September 2003, then became managing director of Market Monitor, which Bisnode acquired in 2004.
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