"If I company exceeds the trading halt period they must request to be suspended"
Not so Miles!
Check out Point 15 in the link below, re: "Back-to-back" Trading halts:
http://www.asx.com.au/ListingRules/guidance/gn16_trading_halts.pdf
These can be given under certain circumstances. I have seen 2 or 3 in recent times
cheers