It's probably likely that they make a better return on their cash management than the rate on these bonds?
If they really have investment opportunities that they are convinced will surpass 3.7% return, why aren’t they just using their existing liquid assets. I agree with other commenters that these funds are either in preparation for a large acquisition or just a dumb decision resulting from irrational and inefficient buracracy common to all large companies.
http://www.businessweek.com/magazine/content/10_23/b41810335...