UPDATE 1-PKN posts Q4 net loss on writedowns, sees margins fall

* Q4 net loss 276 mln zlotys
* Loss due to writedown at Czech unit
* Sees margins down in January

(Adds detail, background)
WARSAW, Jan 23 (Reuters) - PKN Orlen, Poland's top
refiner, has swung to a 276 million zloty ($88 million)
fourth-quarter net loss, hit by a writedown at Czech unit
Unipetrol.
The state-controlled refiner also said on Wednesday margins
continued to shrink, with its joint model refining margin and
Ural/Brent crude price differential down to $2.9 per barrel this
month.
Refiners across Europe are seeing margins squeezed as a
slowdown in demand because a faltering economy has left the
industry with excess capacity.
PKN's sales in Poland were down because of a drop in fuel
consumption, partly offset by an increase in volumes in Czech
and German markets.
PKN had said it would post an operating loss of over 700
million after a 4.5 billion Czech crown ($233 million)
impairment charge to reflect the drop in asset values and an
intention to sell some of those assets.
On Wednesday, the company said it made a fourth-quarter
operating loss of 738 million zlotys.
Before last week's trading statement, analysts had expected
PKN Orlen to post a net profit of 350 million zlotys. The group
earned 619 million zlotys in the 2011 period.
($1 = 3.1406 zlotys = 19.2725 Czech crowns)

(Reporting by Agnieszka Barteczko; Editing by Dan Lalor)