Updated from April 21

Juniper ( JNPR) posted a solid first quarter Wednesday as the company pushes into the Net security business.

Its shares slipped 2% early Thursday as investors worried about potential integration problems on its big NetScreen acquisition.

For its first quarter ended March 31, the Sunnyvale, Calif., maker of telecom networking gear posted a profit of $34 million, or 8 cents a share. That's up from $4 million, or a penny a share, a year ago. Revenue rose 43% from a year earlier to $224 million.

On a so-called non-GAAP basis, excluding certain costs, latest-quarter earnings were 9 cents a share, a penny ahead of the Wall Street consensus estimate.

Cash provided by operations was $72.8 million for the first quarter, compared to cash provided by operations of $12.4 million for the same period last year.

Last week Juniper closed its buy of NetScreen Technologies, an Internet security outfit.

"The results posted by both Juniper and NetScreen as separate companies in the first quarter were strong in all areas," said CEO Scott Kriens. "The strategy behind the decision to make this acquisition is to leverage the strength of both companies, and these results are a key step in executing our plan to extend Juniper's leadership position in the industry."

On a conference call with analysts Wednesday, Kriens explained the company's motivation in acquiring the network security device maker. Kriens stressed that despite what critics say, the move wasn't done to address a weakness in the product lineup, but to "combine strength with strength."

But an executive on the call said it may take six months of integration between Juniper and NetScreen to see progress on the sales and synergies.

Juniper slipped 64 cents to $25.19 early Thursday. One Wall Street observer noted that the so-called whisper number on revenue was about $230 million in the first quarter.

Even so, CIBC World Markets analyst Steve Kamman calls Juniper's results strong. He says early postclose trading isn't always the best indicator of what a stock will do. He points out that the company's deferred revenue levels jumped $25 million, or 25% sequentially. "Posting $100 million in deferred revenues says a lot in a seasonally weak quarter," says Kamman, who has a buy on the stock. CIBC has no underwriting ties to Juniper.