Nvidia Corp forecast quarterly revenue above expectations, lifted by sales of its mobile chips as it fights off growing competition in the personal computer graphics chip market.

The maker of graphics chips for PCs grabbed center stage early this year with design wins in tablets and phones using Google Inc's Android platform and made by Samsung Electronics <005930.KS>, Motorola Mobility and LG Electronics <066570.KS>.

But competition from Apple Inc's iPad 2 has been fierce, raising concerns that consumers may be buying fewer than expected tablets with Tegra processors.

The company's first-quarter results beat expectations, reducing those worries.

Tegra came in slightly better than we expected, and also the notebook graphics came in better, said Stifel Nicolaus analyst Kevin Cassidy. It seems like the industry concerns about Tegra inventories building might not be warranted.

Revenue from Nvidia's consumer products group, including Tegra, jumped 78 percent sequentially to $122.6 million in the first quarter, more than some analysts had predicted.

Nvidia said second-quarter revenue would rise 4 to 6 percent from the first quarter, implying revenue of $1 billion to $1.02 billion. Analysts on average had forecast $992.5 million in revenues for the current quarter, according to Thomson Reuters I/B/E/S.

The company, a new player in the booming mobile market, reported GAAP net earnings of $135.2 million, or 22 cents a share, for the quarter ending May 1, compared with a net profit of $137.6 million, or 23 cents a share, in the year-ago period.

Non-GAAP earnings per share were 27 cents and first-quarter revenue fell 3.97 percent to $962 million.

Analysts on average expected net profit of 19 cents a share and revenue of $947.8 million in the first quarter.

Shares of Nvidia spiked 3.4 percent briefly in extended trade and then trimmed their gain to less than 1 percent. The stock closed up 3.17 percent at $20.50 on Nasdaq.

(Reporting by Noel Randewich; Editing by Richard Chang)