By Rex Crum, MarketWatch

SAN FRANCISCO (MarketWatch) -- Tech stocks started the week mixed Tuesday, as Research In Motion Ltd. and Apple Inc. advanced, but the bulk of the sector remained in the red.

RIM (RIMM) shares climbed more than 11%, to $17.63 following reports that the BlackBerry maker could sell its hardware business. RIM Chief Executive Thorsten Heins reiterated to a German newspaper that the company is continuing with a strategic review of all of its business operations.

Apple (AAPL) was up 77 cents a share, at $500.67 a day ahead of its fiscal first-quarter report. On Tuesday, Verizon (VZ) said it activated 6.2 million iPhones during the fourth quarter of 2012, with almost half of the activations being Apple's iPhone 5. Brian Marshall, an analyst with ISI Group, said Verizon's report is "a solid number supportive of our estimate of 48 million total iPhones," sold in the December quarter.

Google Inc. (GOOG) shares were off by about 1%, at $697.83 in advance of the Internet giant's quarterly results, set for after the close of trading Tuesday. Analysts expect Google to show gains from more of its ad business.

International Business Machines Corp. (IBM) shares rose 50 cents, to $194.96, while Advanced Micro Devices Inc. (AMD) was down slightly to $2.43 a share and Texas Instruments Inc. (TXN) shed 28 cents a share to trade at $33.25. All three companies are also scheduled to release quarterly reports after Tuesday's market close.

The Nasdaq Composite Index (RIXF) gave up 9 points to slip to 3,125, and the Philadelphia Semiconductor Index (SOX) and the Morgan Stanley High Tech 35 Index (MSH) were also in the red.

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