Teesside-based PD Ports has accepted a £260m takeover offer from Babcock & Brown Infrastructure (BBI) Group.
Teesport is one of the largest in Europe
The bid trumps last month's £246m offer put forward by Australian consortium Endeavour which had been backed by PD Ports' board.
However, PD said it had now switched its backing to the higher bid from BBI "and advises its shareholders not to accept the offer from Endeavour".
PD Ports owns Teesport, Britain's second-largest port by volume.
The company also runs a port services arm including warehousing, distribution and freight forwarding from several UK locations.
"BBI invests in quality long-life infrastructure assets that have been well managed by competent and focussed executive teams," said BBI chairman Phillip Green.
"PD Ports fits well within our investment criteria, providing stable cash flows with attractive measured growth opportunities."
The Endeavour consortium was made up of an alliance of private equity group 3i, Australian financial services firm Challenger and Australian fund manager Industry Funds Management.
Endeavour had bid 142 pence per share, including the retention of the interim dividend of 1.5 pence. However, the BBI bid is worth 150 pence per share, also including the interim dividend.
The BBI offer values PD Ports at about £260m. BBI has also offered £77m for bonds which are held by the port company.
After the BBI announcement the board of Endeavour Ports said it was "considering its position" and that a further announcement would be made in due course.