13:37 Jan 12 

but most of the stuff I see these days in English says 'bidders'

13:35 Jan 12 

As Nikki, says, both are perfectly valid; it really depends which terminology you may have used elsewhere; once you have started with 'call for tenders', it's generally better to stick with 'tender' throughout. Unless you get stuck later with something like a 'bid bond'...!

Personally, I always think that 'bidder' reminds me of an auction, hence I prefer to stick with 'tenderer' — though what they submit might perhaps sound better (especially if repeated often!) as a 'bid'.

13:27 Jan 12 

As the term 'soumissionnaire' is used to describe an individual, a company or a firm who submits, then tenderer or bidder are possible. http://termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&s...

How about putting "tenderer/bidder"?