The full, true reasons have never been revealed but the proceeds were used to buy other currency like euros. The B.O.E. was against the sale and were 'sidestepped' by Brown who pushed the auction through. One big error was to pre-announce the sale which due to investment manipulation resulted in a fall in gold price but the euro increased in value meaning less were bought.
It was not the smartest move but the U.S.A. has no gold in Fort Knox that it owns---look at the dollar and their credit rating
I honestly believe it wasn't just to finance Loopy Labours social engineering and demographic change in the U.K. but more to do with world currencies and banking---the end result being it didn't make a blind bit of difference in the end ;D

That laughing idiot Heath--responsible for us being embroiled in the E.U. [twat >] sold more gold reserves when he got his paws on it. Don't forget the other Tory no mark Major who lost £billions trying to prop up the £ artificially with his muppet 'Badger' Lamont--ERM fiasco

The whole thing is a complex murky slime filled sewer powered by greed and manipulated by egotistical ,self promoting,wealth obsessed low lifes >