Oct 18 (Reuters) - Europe's biggest meal delivery company Just Eat Takeaway.com raised its full-year core profit outlook on Wednesday, citing growth in Britain, Ireland and Northern Europe.

It forecast adjusted earnings before interest, taxes, depreciation and amortisation (EBITDA) of about 310 million euros ($327.8 million) for 2023, up from its previous guidance of about 275 million euros.

Following a boom in food deliveries during the pandemic, the sector is seeking to transition to a rational profitability model even as they invest more in marketing to avert a churn in customers.

Just Eat returned to gross transaction value (GTV) growth in the third quarter in Northern Europe, which grew 6%, and Britain and Ireland with a 4% increase, but posted an 11% drop in North America.

It expects its GTV, a common metric for e-commerce firms, to decline about 4% this year, at the low end of its previous range of between -4% to +2%.

The company expects its free cash flow to break even in the second half of 2023 and stay positive thereafter. It had previously targeted positive free cash flow before working capital by mid-2024.

Just Eat also said it would launch a new share buyback programme of up to 150 million euros. ($1 = 0.9457 euros) (Reporting by Michal Aleksandrowicz in Gdansk; editing by Milla Nissi)