Saudi Aramco value in bank research varies by more than $1 trillion - sources

(Reuters) - Valuations for Saudi Aramco vary by more than $1 trillion, according to fund managers who have seen banks' research, underscoring the uncertainty hanging over what could be the world's largest stock market listing.Fund managers are poring over bank research after Aramco on Sunday announced its intention to float on the Riyadh stock market.Sources have told Reuters that Aramco could offer 1%-2% of its shares, raising as much as $20 billion to $40 billion. A deal over $25 billion would..