Council approved the expansion work in March.

The City of Ottawa admitted on Friday that SNC-Lavalin's bid did not meet the minimum score threshold of 70 per cent, and was still allowed to continue with the bidding process for the Trillium Line expansion.

A memo sent to city council by city manager Steve Kanellakos detailed responses to questions posed by Councillor Diane Deans in March, a vocal critic of the transparency of the procurement process.

The Montréal-based company, under the name TransitNext, won the $663-million contract to build the Trillium Line expansion.

Deans and other councillors shared reservations on the process. A CBC Ottawa report in March cited sources that suggested TNext didn't achieve the technical scoring threshold.

Council was informed at the time that all bids for the Trillium Line were 'compliant'.

The city finally revealed the details of the scoring on Friday, and disclosed that SNC-Lavalin's actual score was 67.27 per cent.

They were outscored by their competitors on the technical aspects by a wide margin. Trillium Extension Alliance scored 84.91 per cent, while Trillium Link scored 85.78 per cent.

The memo explains why SNC-Lavalin's bid was still chosen.

According to the city, subsection 6.5.2(4) of the RFP says that the Sponsor of the procurement process may, in its sole discretion, determine whether the proposal will continue to be considered in the RFP Process.

There is no word on who the sponsor is.

The city added "The requirements to achieve a minimum of 70 per cent in the technical scoring, therefore, was not an absolute pass/fail".

The bid by SNC-Lavalin outpaced its competitors by a wide margin on the financial aspects of the bid.

When combined, TransitNext became the highest-ranked bidder.