A retired senior City of Montreal engineer says collusion became rampant on local sewer contracts about a decade ago and that he was pocketing kickbacks galore.

Gilles Surprenant was back on the stand for a third day at Quebec's corruption inquiry, where he went over details of 91 city contracts in which he was involved.

Surprenant, who was the city official in charge of planning and budgeting for public works projects, testified he received kickbacks from construction bosses ranging from $3,000 to $10,000 per contract. In one bigger deal, he pocketed about $20,000.

He told the Charbonneau commission he walked away with between $50,000 and $60,000 in 2000 alone.

The amounts he received on each project weren't fixed, Surprenant said. Some construction bosses were more generous and would occasionally give close to one per cent of the value of a contract, while sometimes it was far less. The average bribe, he said, was around 0.5 per cent.

Surprenant has admitted he collected as much as $600,000 in kickbacks over a 20-year period.

He also received numerous tropical holidays, expensive meals and concert and hockey tickets.

Surprenant said collusion was rampant among the companies bidding on City of Montreal tenders, and it was happening on contracts big and small.

He said he artificially increased the price of contracts determined by a computer program to meet the requests of construction companies working in the cartel.

According to Surprenant, the construction bosses he dealt with were:

Joe Borsellino of Garnier Construction.

Lino Zambito of Infrabec Construction.

Now-deceased Tony Conte of Conex Construction.

Paolo Catania of Frank Catania & Associates.

Antonio Catania and Paolo Catania of Catcan Enterprises.

Domenico Arcuri or Dominic Cammalleri of Mirabeau Construction.

Antonio Bentivegna of Bentech Construction.

Francesco Capello of Super Excavations.

Domenico Aloisio of ATA Construction.

Joey Piazza of TGA Montréal.

Surprenant repeated Tuesday that his bosses always signed off on his work.