Trina Solar (TSL) is down nearly 10% in premarket trading after beating estimates for both EPS and revenues for the quarter but guiding below for Q4 and full year 08.  The company reported an EPS of 1.17, good for a 318% increase over the year ago quarter and topping estimates by .07 on revenues of 290.7 million (beating estimates by about a million). 

However, it’s always about guidance and it wasn’t good.  The company cut its full year forecast by $50 million to $800 – $850 and Q4 estimates to $190 – $210 million vs the consensus of $275 million. 

“Despite further rising silicon costs, over the last four reporting quarters we have exceeded our aggressive goals for output, revenues and operating margin. In the third quarter we again demonstrated the ability to leverage on our integrated manufacturing capabilities, enhanced further by significant improvements in operating efficiencies and cost controls as measured by our operating expenses. We are also pleased by the recently announced expansion of our product portfolio via our in-house developed UMG-based module product. This timely offering is expected to address increasing customer demand for lower cost modules, with initial sales expected in fourth quarter of 2008.