By Rex Crum

Technology stocks were mostly lower in afternoon trading Monday, as the Nasdaq Composite Index led a broad sell off on Wall Street on concern about how big tech companies will do in the coming earnings season.

The tech-heavy Nasdaq (RIXF) fell almost 21 points to 1,775, while the Philadelphia Semiconductor Index (SOX) gave up 2%. The Morgan Stanley High Tech 35 Index (MSH) was also down by more than 1%.

Among leading tech stocks, losses came from Apple Inc. (AAPL), Microsoft Corp. (MSFT), Hewlett-Packard Co. (HPQ), IBM Corp. (IBM), Cisco Systems Inc. (CSCO) and Intel Corp. (INTC).

Data Domain (DDUP) was one of the few notable advancers, as the disaster-recovery technology company's shares rose 91 cents, or 2.8%, to $34.13.

Data Domain got a lift after EMC (EMC) raised its all-cash bid for the company to $33.50 a share from its previous offer of $30 a share. Data Domain has agreed to be acquired by NetApp (NTAP) for $30 a share in cash and stock, but EMC's new bid may cause Data Domain to re-visit the latest offer.

Before the market opened, NetApp said it received regulatory clearance to proceed with acquiring Data Domain, which has scheduled a special shareholders' meeting for Aug.14 to approve the deal.

Data Domain has been in play in late May since it reached a deal to be acquired by NetApp for $25 a share. Since then, NetApp and EMC have increased their offers for the data-services technology company.

Data Domain shares rose 92 cents, or 2.8%, to $34.13 following EMC's latest offer. EMC's stock was down 2 cents a share at $12.77, while NetApp gave up 14 cents a share to fall to $18.82.