SAN FRANCISCO — Dell Inc. forecast a fourth straight quarter of declining sales as diminishing demand for PCs overshadows efforts to diversify into making more profitable products for data-storage centers.
Quarterly revenue will be $14 billion to $14.4 billion, the company said — less than the $14.5 billion average estimate of analysts, according to data compiled by Bloomberg. A year ago, revenue was $16 billion.
Dell, the number three maker of personal computers, is struggling amid a deep slump in demand as companies wait to upgrade machines and consumers turn to smartphones and tablets.
Even as Dell works to mitigate the decline by adding storage, networking gear, software, and services through acquisitions, the company still gets half its sales from PCs.
‘‘They’ve been talking about changing the last five years,’’ said Shaw Wu, an analyst at Sterne Agee & Leach Inc.
‘‘They’re in a very tough position, plain and simple.’’
Dell stock has dropped 35 percent this year.