By Dan Gallagher, MarketWatch

SAN FRANCISCO (MarketWatch) -- The selloff on the tech sector moderated somewhat by Friday's closing bell, though most stocks in the group still ended up well in the red with few exceptions -- mostly Facebook Inc.

Facebook (FB) shares were up 1.2% to close at $27.39. The social network hosted an event on Thursday, at which it unveiled a new piece of software called Home for Android-based smartphones. Argus Research upgraded the social network to a buy rating on Friday.

"We see Facebook Home as a way for the company to strengthen its presence in mobile computing without jumping into the hardware business or even developing its own operating system," analyst Joseph Bonner wrote in a note to clients.

But most tech firms felt the crunch of a broad market selloff, after job gains came in at their lowest level in 9 months. The Dow closed down more than 40 points after shedding more than 150 points earlier in the session.

The Nasdaq Composite Index (RIXF) closed down 0.7% to 3,204 while the Philadelphia Semiconductor Index (SOX) fell 0.5% and the Morgan Stanley High-Tech Index fell by 1.3%.

One major weight on the tech sector came from F5 Networks (FFIV), which slid more than 19% to close at $73.21 after the company lowered its earnings and revenue outlook for the second fiscal quarter, citing weaker sales to telecom customers.

At least four brokers downgraded the stock following the warning. The report also took down other telco equipment stocks; Juniper (JNPR) fell more than 3% by early afternoon, while JDSU (JDSUD) and Cisco Systems (CSCO) shed more than 2% each.

Hewlett-Packard (HPQ) fell 1.5% after announcing that Chairman Ray Lane was stepping down following a weak showing of shareholder support at last month's annual meeting.

Zynga (ZNGA) said venture capitalist John Doerr of Kleiner Perkins has joined its board of directors. The social game maker's stock rose by 2.9% to close at $3.55.

Amazon.com (AMZN) CEO Jeff Bezos made a "significant investment" in the Business Insider website, according to an internal memo released by Business Insider CEO Henry Blodget. Bezos was part of a group that invested $5 million in the site.

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(END) Dow Jones Newswires

04-05-13 1614ET