Subject to the satisfactory completion of financial, legal and value for money considerations, the Welsh Government may then proceed towards a purchase of the airport.
Announcing the agreement, the First Minister said:
"Over the past 12 months, I have repeatedly emphasised the importance to Wales of a dynamic international gateway airport in Cardiff.
"During the course of the year we have developed a very constructive and positive relationship with TBI. Together we have been discussing how best to develop the airport to position it for the challenges ahead.
"I can today announce that the Welsh Government has agreed with TBI to progress towards the purchase of Cardiff Airport. Such an arrangement would enable us to develop a more coherent approach to our national infrastructure planning, and integrate the airport into our wider economic development strategy."
The Business Minister Edwina Hart said:
"The message from business leaders and tourism operators across Wales is clear; strong, international transport links are vital to our prosperity, and key to future economic growth.
"Subject to satisfactory due diligence, our investment in Cardiff Airport has the potential to create many exciting possibilities for the Welsh economy – boosting opportunities for international trade, and helping to increase visitor numbers to Wales."