* Cautious on third quarter
* Stock up 2.3 percent before forecasts (Adds quotes and details)
TAIPEI May 13 (Reuters) - Netbook PC pioneer Asustek Computer (2357.TW) trimmed its second-quarter revenue forecast on Thursday, citing the effect of a weak euro on overseas revenue.
Asustek's second-quarter revenue is likely to be about the same as that of the first quarter, compared with a previous forecast of flat to up to 10 percent growth, President Jerry Shen told reporters.
"At present, the currency is a big problem," Shen said on the sidelines of a news conference where Asustek introduced a new line of notebook PCs.
"Everybody in this industry is facing the same problem. For the third quarter, it might not be as strong as it was in the past years," he said, without giving any forecasts.
Technology demand typically picks up in the third quarter due to back-to-school demand and pre-Christmas buying.
Asustek said in April it saw notebook PC shipments in the second quarter flat to up 10 percent over the first quarter and netbook shipments flat to up 5 percent. [ID:nTOE63T06F]
However, Shen said the company's 2010 notebook shipment target is unchanged at 18 million units.
His comments came after the Taipei stock market closed on Thursday. Asustek shares rose 2.31 percent, outpacing the main TAIEX's .TWII 2.21 percent rise. (US$1=T$31.8) (Reporting by Baker Li and Roger Tung, Editing by Jonathan Standing and Jonathan Hopfner)