SanDisk Corp's 19 percent revenue rise surpassed expectations after strong smartphone and tablet demand propped up first-quarter chip prices, as it reaffirmed hopes for a strong 2011 despite supply-chain tangles from Japan.

Sandisk stock slid 2 percent after-hours, but has gained almost 10 percent since Japan's largest-ever earthquake on record on expectations that the subsequent curtailment of chip supply will boost spot prices.

But some analysts warn that persistent disruption to its production from Japan -- which accounts for more than a 10th of global electronics components -- due to intermittent power and unreliable shipping will begin to weigh on sales this quarter.

Sandisk's chip-manufacturing joint venture with Toshiba Corp sources the majority of its components from Asia's second-largest economy. The U.S. company is expected to divulge its forecasts for the second quarter later on Thursday.

We have been actively managing our supply chain following the recent events in Japan and believe we remain on track to deliver a strong 2011, CEO Sanjay Mehrotra said in a statement.

The flash memory supplier said net income was $224 million or 92 cents a share. Excluding items, earnings jumped 8 percent to $1.03 a share from 95 cents a year earlier, exceeding Wall Street's target of about $1.00.

Revenue rose 19 percent to $1.29 billion, also exceeding analysts' average forecast for $1.26 billion according to Thomson Reuters I/B/E/S.

Flash memory demand is roaring as a crucial component in tablets and smartphones. But it is a commodity product and SanDisk's fortunes are in large part determined by the balance of supply and demand in the industry, and its impact on pricing.

The global NAND flash market is expected to rise to roughly $23 billion this year from less than $20 billion in 2010. Sandisk has forecast 2011 revenue of $5.3 billion to $5.7 billion, and gross margin of 39 percent to 42 percent.

Shares of SanDisk slid to $47.89 from a regular-session close of $48.99.

(Reporting by Edwin Chan)