The venture capital backers of Dutch map maker Tele Atlas could make more than €500m ($734m) after vehicle navigation services company TomTom increased its offer by 40% in response to a bid from its rival Garmin.

TomTom raised its offer for Tele Atlas to €30 from €21.25 per share to value the target's equity at €2.9bn and at an 81% premium to its pre-offer share price on 20 July.