** Shares in Skanska SKAb.ST fall 3.9% after the Swedish builder reported Q3 results below forecast
** Jefferies sees Skanska's 658 million Swedish crowns ($69.88 million) impairment in its US property division as the main negative
** Broker adds that the Nordic builder beat expectations elsewhere, driven by higher margin in Construction division and an improved outlook for Nordic and European Commercial
** Jefferies notes focus will be on the US where it expects a negative reaction
** "However, we would see this as a buying opportunity with clear signs of improvement in Skanska's markets," says Jefferies
** The stock was down 4.5% at 08:05 GMT, on track for its worst day since April, if losses hold
($1 = 9.4155 Swedish crowns)
(Reporting by Vera Dvorakova)
((vera.dvorakova@thomsonreuters.com))