UPDATE 2-Trina Solar posts adj Q1 profit, shares rise

* Posts surprise Q1 adj profit; revenue falls 39 pct

* Gross margin improves on lower raw-material cost

* Sees shipping 60 MW to 65 MW of modules in Q2

* Backs 2009 shipment view

* Shares up 9 percent (Recasts; adds details, analyst comment, background; updates share price)

By Adveith Nair

BANGALORE, May 28 (Reuters) - Chinese solar-products maker Trina Solar Ltd (TSL.N: Quote, Profile, Research) posted a surprise quarterly profit before items, as gross margins increased helped by a fall in raw-material costs, sending its shares up as much as 9 percent.

Gross margin for the first quarter was 17.2 percent, exceeding Trina's previous outlook of 15 percent to 17 percent, helped by lower average silicon-purchase prices.

The company had reported margins of 9.6 percent in the fourth quarter of 2008.