Just because that a company has bought other companies in the past does not mean that they can't be bought themselves. It's a question about $$$. Has been done many times before, and is also happening with a lot of other type companies all the time...
What ever happened with CHC by the way, lost track of the proposed sale a year or so back?! Btw, CHC did buy Helicopter Services in Norway 10-12 years back, after it had just previously been buying Lloyds, Bond, Brintel and Court in SA. as far as I remember.