PC unit sales will suffer their first year-over-year decline since 2001 in the wake of the DotCom bust, according to a new report from research firm iSuppli. Analyst Matthew Wilkins said that sequential growth in units sales in the 3rd and 4th quarter will not be enough to offset declines in the first half of the year, making for a yearly decline.

"An annual decline in unit shipments is highly unusual in the PC market," Matthew Wilkins, principal analyst, compute platforms for iSuppli, said in a statement. "Even in weak years, PC unit shipments typically rise by single-digit percentages."

For perspective, he added, "The last decline -- in 2001 -- was a 5.1 decrease in unit shipments due to the extraordinary impact of the DotCom bust, which caused inflated IT spending levels from the previous years to collapse."

The global economic crisis that manifested in 2008 has had a major impact on the technology sector, with Apple being one of the few computer (and electronics) companies that has managed to hold its own in year-over-year comparisons.

For instance, AppleInsider noted that Piper Jaffray analyst Gene Munster told clients in a research note that he believes strong MacBook Pro sales will push Apple ahead of consensus numbers for the June quarter. Apple reports those numbers next Tuesday, July 21st.

Back to the broader PC industry: Mr. Wilkins of iSuppli expects Global PC shipments to decline to 287.3 million units in 2009, down 4 percent from 299.2 million in 2008. The company had previously forecast a 0.7% increase for the year.