ZURICH, March 28 (Reuters) - The Swiss National Bank (SNB) sold 22.7 billion Swiss francs ($25 billion) worth of foreign currencies in the fourth quarter, the central bank said on Thursday.

The amount was a sharp decrease from the 37.6 billion francs in forex sold by the SNB in the July to September period. ($1 = 0.9057 Swiss francs) (Writing by Dave Graham)