UPDATE 1-Flextronics eyes $3.5 bln in notebook PC sales by 2011

* Enters notebook PC sector in challenge to bigger players

* Aims $3.5 billion in revenue by 2011

* Quadruples notebook manufacturing staff numbers in Taiwan

* Follows acquisition of Arima Computer last year

By Kelvin Soh

TAIPEI, July 13 (Reuters) - Electronics giant Flextronics (FLEX.O) will quadruple its notebook PC workforce in Taiwan, in a major push that would pit it against established contract PC makers such as Quanta (2382.TW) and Compal Electronics (2324.TW).

The addition of 1,500 engineers to the Singapore-based firm's FLEXComputing Taiwan unit will bring the total to 2,000, as it looks to grab a piece of a fast-growing global notebook PC market expected to pass traditional desktop PCs this year in unit sales, sources told Reuters on Monday [ID:nTP107611]

The move follows Flextronics's acquisition of PC contract manufacturer Arima Computer last year.

"The unit in Taiwan will focus primarily in research and design work because that's where the major suppliers are," said one of the sources, who spoke on condition of anonymity because they are not authorised to speak to the media. "Manufacturing will still be done at the company's factories in China."