Shares in ITV PLC (LSE:ITV) dropped over 8% to 68.25p after Virgin Media owner Liberty Global (NASDAQ:LBTYA) sold half its stake, having held it for just over a decade.
The US company sold 193,365,540 shares, equivalent to selling a 5% stake in the broadcaster for approximately £135 million.
This reduced its stake that reached 10% in the summer of 2015, since when the shares have collapsed by around 75%.
Liberty Global has promised not to sell further shares for at least two months.
At the time of its 2015 purchase, close to all-time highs over 270p, Liberty said ITV "is a well-run company with attractive growth potential, and we are pleased to increase our position as their largest shareholder".
It sparked speculation over whether Liberty may make a bid to fully buy ITV.