Krayem, 23, was charged on April 9th with “terrorist murders” over last month's suicide blasts in the Belgian capital, but the new charges reflect growing links between the attackers and those who carried out November's jihadist carnage in Paris.
“His fingerprints were found at several hideouts used during preparations for these attacks,” Flemmish television station VRT reported.
Belga news agency confirmed the fresh charges, citing prosecutors.
The prosecution service and Krayem's lawyers were not immediately reachable, but prosecutors are due to hold a news conference on Wednesday.
The coordinated bombings at Brussels airport and a metro station near European Union headquarters, claimed by the Islamic State group, left 32 people dead months after the Paris attacks killed 130 people.
The authorities suspect Krayem, a Swede of Syrian origin, of buying the bags used for the Brussels bombings.
He was filmed on CCTV with Maalbeek metro station bomber Khalid El Bakraoui minutes before the bomb went off.
Krayem's lawyer Vincent Lurquin told reporters last week that his client had also planned to blow himself up but decided not to go ahead with it.
Investigators are still looking for the backpack Krayem was wearing that day.
Three men detonated suicide bombs in Belgium's worst-ever terror attack: brothers Ibrahim and Khalid El Bakraoui and Najim Laachroui.
A fourth man, Mohamed Abrini, the so-called “man in the hat” who accompanied the two airport bombers but did not detonate his own device, was arrested in Brussels on April 8th. He has also been charged over the Paris attacks.
Initial investigations suggest that the Brussels attackers had planned to hit France, but with police on their trail, decided Belgium was an easier target.