WRAPUP 1-Frontier Oil, Holly hit by weak refining environment

* Frontier rev down 45 pct

* Holly rev down 13 pct, but EPS beats est * Frontier adj loss wider-than-expected * Alon loss also trails market view

* Delek posts surprise Q3 loss BANGALORE, Nov 5 (Reuters) - Oil refiners Frontier Oil Corp (FTO.N) and Holly Corp (HOC.N) reported lower quarterly sales as demand and prices for refined products remained weak. Frontier Oil posted a 45 percent fall in revenue and an adjusted quarterly loss that was wider than market estimates on weak refining margins. [ID:nBNG505732]

Refiners margins were hit hard as a sluggish global economy hurt demand for products like diesel and swelled stockpiles to record levels.

Holly Corp (HOC.N), whose earnings beat Wall Street expectations on increased refinery production, also posted a 13 percent fall in revenue and warned that weak market condition will stay. [ID:nBNG328511]

"The refining industry will remain challenging until economic activity increases and refined product inventories are reduced," Holly's Chief Executive said in a statement.

Smaller rival, Delek US Holdings Inc (DK.N) also blamed the weak refining environment for its surprise quarterly loss. [ID:nWNAB0485]

"Challenging Gulf Coast refining economics weighed heavily on our overall profitability during the third quarter 2009, serving to offset modest gains in our other segments," Delek's Chief Executive Uzi Yemin said in a statement. [ID:nWNAB0485] On Wednesday, Alon USA Energy Inc (ALJ.N), which posted a third-quarter loss that was wider than expected, said its results reflect the impact of industry-wide declines in light product crack spreads.

"There was a continual reduction in the sweet/sour and light/heavy spreads on crude oil, both of which negatively impacted the operating margins at our Big Spring and California refineries," Alon Chief Executive Jeff Morris said in a statement.

Lower-grade, or sour crude oil which some of the refineries process has lost much of the cost advantage over higher-grade crude.

Frontier shares were trading down 1.5 percent at $13.58, while Holly shares were flat in morning trade on the New York stock exchange.

However, Alon shares rose as much as 8 percent after the company said it moved the scheduled turnaround at its 83,100 barrel-per-day Krotz Springs refinery in Louisiana to November 2009 from the first quarter of 2010. [ID:nN05405126]. (Reporting by Hezron Selvi in Bangalore; Editing by Pradeep Kurup)