UPDATE: Stifel Nicolaus Decreases Target to $31.50 on Quanta Services

Stifel Nicolaus cuts its price target on Buy-rated Quanta Services (NYSE: PWR) by half a dollar to $31.50 a share on reduced forecast, driven by the company's weak guidance.

Stifel Nicolaus says, "We forecast 27.3% revenue growth to $5.88 billion and a 7.5% operating margin vs. 5.4% in 2011. Our forecast is above company guidance. 2012 EPS growth is derived from 1) $0.32 of incremental EPS from the Electric Power segment, and 2) $0.21 of incremental EPS from the Gas and Pipeline segment. We believe there is upside to our 2012 forecast, particularly in profit margins."

PWR closed at $21.27 a share on Wednesday.