The prosecutor said in a statement Panzeri signed a "repentance agreement", where he commits to make "substantial, revealing, truthful and complete statements" about parties involved, and crimes committed, in the case.

In particular, he will inform investigators about how the operations were conducted, the financial arrangements with other involved countries, the financial structures that were set up, including their stakeholders and benefits, the involvement of known and unknown people within the investigation, including the identity of the individuals he admits to having bribed.

His sentence will include one year of prison time and four years of suspended jail term, a fine and the confiscation of all assets acquired, estimated at one million euros ($1.08 million), the prosecutor's spokesperson Eric Van Duyse told Reuters.

"It's a win-win situation", he said.

Without the memorandum, Panzeri would receive "a much heavier prison sentence" and he was "sufficiently in the center of the dossier to provide (Belgian investigators) relevant information," Van Duyse said, adding that if Panzeri failed to provide satisfactory information, the memorandum would be cancelled.

It is the second time since the law that allows such agreements was introduced in 2018 that these proceedings have resulted in the signing of a memorandum.

The European Parliament on Monday began a month-long procedure to waive immunity from prosecution for two lawmakers.

EU Parliament President Roberta Metsola told the assembly in Strasbourg that Belgium had requested immunity be lifted for Italian Andrea Cozzolino and Belgian Marc Tarabella, both of the centre-left Socialists and Democrats.

Panzeri, Greek EU lawmaker Eva Kaili, along with two others are currently in Belgian custody facing charges of corruption, money laundering in relation to alleged payments from Qatar and Morocco.

($1 = 0.9260 euros)

(Reporting by Marine Strauss and Charlotte Van Campenhout, additional reporting by Clement Rossignol; Editing by William Maclean and Tomasz Janowski)

By Marine Strauss and Charlotte Van Campenhout