Pre-emptive rights are very important to Apache's joint venture partners (incl Tap) as a negotiating tool. If Apache spins off those assets into a new company, of which they have no control over, then they have effectively sold those assets and that would trigger pre-emptive rights
My view appears to be supported in the case Beaconsfield Gold NL & Ors v Allstate Prospecting Pty Ltd & Ors1
http://www.allens.com.au/pubs/res/foresnov06.htm