UPDATE 4-Qatar tops up war chest by selling VW pref shares

* Gas-rich state sells pref shares worth about 1.5 bln euros

* Shares placed at average 60 euros apiece - source

* Stake about a quarter of all VW preference stock

* Qatar plans to increase its voting stake to 17 pct

* VW pref shares end down 15.8 pct, ords down 8 pct

(Recasts with placement price)

By Christiaan Hetzner and John Irish

FRANKFURT/DUBAI, Nov 10 (Reuters) - Qatar has sold half its Volkswagen preference shares (VOWG_p.DE), cashing in on recent gains and raising around 1.5 billion euros ($2.4 billion) for possible future deals.

VW preference shares -- widely expected to join Germany's blue-chip DAX index .GDAXI once VW ordinary voting shares (VOWG.DE) drop out due to the low free float -- closed down nearly 16 percent at 60.22 euros.