There's one reason, and one reason only, that China is interested in buying up a bunch of Italian state-owned businesses. And, that's ENI, the Italian oil company. (Here's a more detailed list of what's for sale.) ENI, per Wikipedia, is a major producer of light, sweet, quality North African crude, as well as having operations around the globe, incliuding China.
Beijing gets ENI's drilling expertise, a new foot in the door in cis-Saharan Africa, possible new angles on Middle Eastern oil operations and more. What's not to like, if you're China?
If you're Italy, sounds both dumb and desperate.