By Rex Crum, MarketWatch SAN FRANCISCO (MarketWatch) -- Tech stocks rose Tuesday, led by semiconductor stocks following Texas Instruments Inc.'s deal to buy National Semiconductor Corp. for $6.5 billion and a rebalancing of the Nasdaq 100 Index that trimmed the influence of Apple on the market gauge. The Philadelphia Semiconductor Index (SOX) climbed almost 3%, while the Nasdaq Composite Index (RIXF) climbed more than 15 points to 2,804. "There have been some crazy cross currents impacting tech," said Brian Marshall, an analyst with Gleacher & Co. "Secular names, which offer the best growth opportunities have all been taken out back behind the woodshed. Then, on the other hand, we have safer, more mature names with limited growth profiles such as IBM, Dell and SAP, actually outperforming this year." National Semi (NSM) shares surged more than 71% to $24.13 in the wake of the acquisition, which was announced late Monday. The deal, which has been approved by the boards of both companies, values National Semi at $25 a share. TI (TXN) shares rose 64 cents to $34.75 Tuesday. The deal marks a major consolidation in analog chips, where TI and National Semi both have large market shares. Among other chip stocks, big gains came from Intersil Corp. (ISIL), up $1.18 a share, or almost 10%, to $13.30; Semtech Corp. (SMTC), which rose $1.79 a share, or 7.4%, to $26.15, and On Semiconductor Corp. (ONNN), up 50 cents a share, or 5%, to $10.16. Apple Inc. (AAPL) shares shed 26 cents to $340.95. The Nasdaq OMX (NDAQ) said it was rebalancing the Nasdaq-100 Index (NDX) and would lower Apple's weighting to about 12% from more than 20%. Nasdaq said the move was being made to better reflect the market capitalizations of the index's stocks and would take effect on May 2. Cisco Systems Inc. (CSCO) shares were up 29 cents at $17.36. In a letter posted to Cisco employees on a company blog, Cisco Chief Executive John Chambers that while he believes the networking giant's strategy is sound, the company's operational execution has been lacking and "we have disappointed our investors and we have confused our employees." Google Inc. (GOOG) fell $16.87 a share, or almost 3%, to $570.75. Bloomberg News reported that Google could be subject to a U.S. Federal Trade Commission antitrust investigation of the company's share of the Web search market. Among other tech stocks, gains came from Dell Inc. (DELL) as well as Dow Jones Industrial Average components Microsoft Corp. (MSFT) and Hewlett-Packard Co. (HPQ).