The amount for which an asset could be exchanged, or a liability settled, between knowledgeable, willing parties in an arm's length transaction.

IIMM

Fair Value is "the amount for which an asset could be exchanged, or a liability settled, between knowledgeable, willing parties, in an arms length transaction." This is equivalent to the market value of the asset where one exists. If there is no market the fair value can be determined on a cost of acquisition basis.

LGAM

Fair Value is the best estimate of the price reasonably obtainable in the market at the date of valuation where a market exists. This is often not the case for existing infrastructure assets, in which case fair value is depreciated replacement cost.

AIFMG 2009