While I agree with the way you put things down here in this post, one thing that I would like to remind you of, is that STO does not have to sell it's 19.99% of the shares in ESG they hold, not the 35% of the ESG tenements that they do hold.
So, even if someone the likes of BG, Shell or even AGL as you wrote, will come out with a good offer that we all will be very pleased with, STO can still remain a passive investor with whoever decide to make the move on us.
On the other hand STO is also used to have JV's with may other companies out there. So nothing will change for them.
Buddy
ESG Price at posting:
84.5¢ Sentiment: None Disclosure: Held