To choose a law firm through a competitive bidding process sounds admirable, but if a multi-defendant lawsuit presents the opportunity and if codefendants are at the same time selecting their counsel, a law department may not have the luxury of a competitive-bid process. Some of the law firms that might be very well able to represent you will be snatched up by other parties and conflicts of interest will eliminate them from the competition.
I doubt that law firms make a habit of turning down the first decent-lookin’ feller who asks them to dance.
On the other hand, in a lawsuit that names many companies in the same industry, opportunities exist for shared and joint representation, which can dramatically reduce the costs to the defendants who can take part.