Amsterdam's Schiphol Airport on Friday unveiled an investment plan totalling six billion euros by 2029 to improve infrastructure and working conditions.

One of Europe's major transit hubs has been battling staff shortages with many employees including baggage handlers and security personnel voicing concern about workloads and absenteeism.

"Between 2024 and 2029, Schiphol is investing six billion euros to improve the airport facilities," it said in a statement.

It was the "biggest investment plan in the airport's history," it added.

Schiphol experienced major baggage handling problems two years ago when thousands of suitcases piled up as air travel slowly started up in the aftermath of the Covid pandemic.

Baggage basements, climate control systems, escalators as well as docking piers, taxiways and aircraft stands needed upgrading.

Working conditions too needed improving, the airport said.

"Our infrastructure is the foundation of our service, but is currently far from what we want to offer our passengers as a quality airport in the Netherlands," Schiphol's chief executive Pieter van Oord said.

Schiphol has already invested three billion euros in the expansion and improvement of terminals in recent years.

Friday's announcement came as the air hub presented financial figures for the first six months of 2024.

Passenger numbers were up by 10 percent from last year, with some 31.8 million flyers passing through Schiphol's gates from January to June.

A total of between 65 and 68 million passengers are expected at Schiphol this year, with a total number of flights landing and departing estimated at between 470,000 and 473,000.