Kirkham, who was appointed chief executive in 2001, had previously indicated to the board that after five years in the role he would hand over to a successor.
However, Kirkham will not be bowing out completely. He has been named as a possible candidate to replace TNS chairman Tony Cowling, who is due to leave at the end of the year. If Kirkham is not appointed in this role, he is expected to stay at TNS until October 2006 when his contract runs out.
Lowden joined TNS as finance director in 1999 and in 2003 became chief operating officer, with responsibility for the group's regional operations across the globe.
He has been credited with showing "considerable ability" in operational and strategic management and demonstrating a thorough understanding of the business and its markets.
"We believe that, together with the support of the strong operational management across the group, David will provide the leadership, continuity and strategic thinking necessary for the future successful development of TNS," Cowling said.
Last week, TNS launched its first online Creative Minds access panel, consisting of a specialised group of respondents suited to new product development and market innovation.
The market research giant unveiled a profit hike of nearly 6% in the first half of 2005 compared with the same period last year, however it revealed its UK and US businesses are not as strong as the rest of the group.
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