UPDATE 1-FormFactor posts Q1 loss, sees weak Q2; shares tank

(Recasts, adds outlook, details, share movement)

April 29 (Reuters) - FormFactor Inc (FORM.O: Quote, Profile, Research) posted a first-quarter loss as a weak market for memory chips that are used in personal computers weighed and forecast worse-than-expected second-quarter results, sending its shares down 16 percent.

The maker of wafer probe cards for the semiconductor industry said customers have been dramatically delaying test capacity expansions and pushing out technology transitions due to the weakness in the dynamic random access memory (DRAM) market.

For the first quarter, FormFactor posted a net loss of $18.0 million, or 37 cents per share, compared with a net income of $15.2 million, or 31 cents per share, in the year-ago period.

First-quarter results included about $5.3 million in restructuring costs and $4.5 million, or 9 cents per share, of stock-based compensation.

Revenue from DRAM, the company's largest segment, fell 47 percent to $40.2 million. Total revenue for the quarter was $65.7 million.

Analysts on average were expecting the company to post a loss of 22 cents a share, excluding restructuring charges but including stock-based compensation expenses, on revenue of $65.2 million, according to Reuters Estimates.

For the second quarter, the company forecast a loss of 43 cents to 60 cents a share, excluding restructuring costs, on revenue of $40 million to $55 million.

Analysts were expecting the company to post a loss of 11 cents a share on revenue of $66 million.

FormFactor shares, which closed at $20.07 Tuesday on Nasdaq, were trading at $16.86 after the bell. (Reporting by Jennifer Robin Raj and Bijoy Koyitty in Bangalore; Editing by Deepak Kannan)