By Benjamin Pimentel

The tech sector sank into the red Tuesday morning as shares of Dell Inc. tumbled after the computing giant said it expects slightly lower gross margin.

Dell's (DELL) shares fell more than 7% after the company forecast a decline in second-quarter gross margins.

The Nasdaq Composite Index (RIXF) fell 0.4% to 1,786, while the Morgan Stanley High Tech 35 Index (MSH) was down 0.5%.

The tech sector got a boost from semiconductor shares, as the Philadelphia Semiconductor Index (SOX) rose 0.6% on gains from shares of Applied Materials Inc. (AMAT) and Nvidia Corp. (NVDA).

Intel Corp. (INTC) was mostly flat. The chip giant is scheduled to report second-quarter results after the closing bell, with analysts anticipating signs of a stabilizing market.

Meanwhile, losses from other major tech players took their toll on the sector.

Tech bellwethers Oracle Corp. (ORCL), Microsoft Corp. (MSFT) and Hewlett-Packard (HPQ) were both down more than 1%. Amazon.com (AMZN), IBM Corp. (IBM) and Apple Inc. (AAPL) were also in the red.