It wouldn't necessarily be the case that the companies making use of the letters of credit would be in that position. It would be a case of how they would want to use their cash resources at a particular point in time. It would also be that whatever credit they use for the pension plan is not available for other purposes that the company might consider. So I'm not sure that it would necessarily always be the choice of the company to use a letter of credit. It would depend on the company's investment plans and things that are outside of the pension plan.
Evidence of meeting #14 for Finance in the 40th Parliament, 3rd session. (The original version is on Parliament’s site, as are the minutes.) The winning word was positions.
A recording is available from Parliament.