Mike Danson, who last year sold his research group Datamonitor to Informa for £500 million, has upped his stake at under-offer internet marketing specialist TMN.

As chairman of Datamonitor, Danson, who bought 5,190,000 TMN shares on Wednesday and Thursday at 45p and 50p to take his holding to 7.6 per cent, hired as non-executive director a certain Peter Harkness. Harkness is chairman and 0.2 per cent shareholder of TMN.

On Tuesday this week TMN received a 'possible' offer from AIM marketing peer Tangent Group, in which former Carlton boss Michael Green owns 32 per cent. TMN's shares have risen 8.5 per cent to 51p today, higher than the 50p at which the offer valued them.