Updated from April 22

Shares of communications chipmaker Broadcom ( BRCM) spiked as analysts substantially boosted their profit estimates after the company reported a resoundingly strong first quarter. Late Thursday, Broadcom issued generous June quarter sales guidance on top of consensus-beating revenue for the first quarter of 2004.

The stock was recently up $2.77, or 6.8%, to $43.57.

At CIBC, Allan Mishan called Thursday's results a "monster report," singling out sequential growth of 48% in broadband chips as the most impressive. Broadband now accounts for 29% of sales at Broadcom.

Mishan raised his 2004 earnings per share estimates to $1.30 from $1, with expected revenue at $2.55 billion, up from a prior estimate of $2.35 billion. "As strange as it sounds, Broadcom appears to be trading at a reasonable P/E multiple," wrote Mishan. Based on Thursday's closing price of $40.80, the stock trades at 31 times 2004 EPS and 29 times 2005 EPS -- "not bad given the growth and profitability profile," he concluded. (Mishan has an outperform rating on Broadcom; his firm hasn't done investment banking for the company.)

At Legg Mason, Cody Acree kept his hold rating on the shares, though he praised the quarter in a morning note. "Similar to what we are seeing across the rest of the chip industry, Broadcom's lack of seasonal impact is encouraging evidence of the sector's improving momentum and a level of stronger economic demand, which is now not only being driven by attractive consumer spending, but increasingly being supported by growth in enterprise and infrastructure activity," he wrote.

Acree hiked his sales and earnings estimates for the company by substantial amounts, with the resulting estimates for 2004 about on par with those of CIBC's Mishan.