LSI Logic ( LSI) on Wednesday reported stronger-than-expected first-quarter results, reversing a loss from a year ago and posting a 21% revenue hike. But shares sank in after-hours trading as the chipmaker said second-quarter revenue could fall short of estimates. Shares of LSI recently fell 67 cents, or 8%, to $7.75 in after-hours trading; shares closed the regular session down 41 cents, or 4.6%, at $8.42. Under generally accepted accounting principles, Milpitas, Calif.-based LSI reported net income of $9.1 million, or 2 cents a share, in the first quarter. That compared with a net loss of $122.4 million, or 33 cents a share, in the same period a year earlier, which included restructuring charges. Excluding charges, LSI had pro forma net income of $25.2 million, or 6 cents a share, in the first quarter, compared with a loss of $50.8 million, or 14 cents a share, a year earlier. Revenue rose 21% from a year ago, to $452.4 million. Wall Street analysts expected LSI to earn pro forma net income of 4 cents a share on $450.4 million in revenue in the first quarter, according to Thomson First Call. Looking ahead, LSI projected second-quarter revenue will range from $455 million to $470 million, with GAAP earnings ranging from a penny to 3 cents a share and earnings excluding charges ranging from 6 to 8 cents a share. Analyst estimates were calling for second-quarter revenue at $472 million and pro forma earnings at 6 cents a share.