UPDATE 1-Bouygues expects improved Q3 result despite sales dip

* Q3 sales of 8.378 bln euros vs forecast of 8.453 bln euros

* Reaffirms year outlook

* Telecom sales up 3%, construction flat, roads down 10%

By Leila Abboud

PARIS, Nov 12 (Reuters) - Bouygues (BOUY.PA) said on Thursday it expected improved third-quarter results despite posting slightly lower than expected revenues, dragged down by its roads unit.

Third-quarter sales at the French construction, media and telecom comglomerate fell 4 percent to 8.378 billion euros ($12.56 billion), helped by forecast-beating construction and real estate revenues while telecoms turnover was in line.

Eight analysts polled by Reuters expected sales of 8.453 billion euros.

The group also reaffirmed its full-year forecast for revenue of 31.5 billion euros, which was given in August.

The full third-quarter results are due to be released on Dec. 1, but the group hinted at what was to come.