Some major data center service providers saw their stocks decline drastically, following a guidance adjustment by colocation provider Equinix Tuesday. The sharpest drop in share price was experienced by Equinix itself, whose price per share was down more than 30 percent around 2:30 pm EDT on Wednesday.

Share prices of other providers with different product portfolios were down around the same time. The companies included Rackspace, down about 12 percent;Savvis, down about 11 percent;Digital Realty Trust, down about five percent;DuPont Fabros, down about six percent;and others.

On Tuesday, Equinix announced it expected its 2010 third-quarter and full-year revenues to be below its previous outlook provided at the end of July. The company expects to make between $328m and $330m in sales during the third quarter ÔÇô a 2.2-percent drop from midpoint of the previous outlook. Equinix expects $1.215bn in sales for the full year ÔÇô an adjustment of 1.2 percent down from the previous outlook's midpoint.

In the same announcement, Equinix also increased its adjusted EBITDA outlook for the same quarter and year, attributing the increase to better-than-expected gross margins and lower-than-expected expenses. Its third-quarter adjusted EBIDTA outlook is now more than $140m and full-year outlook is about $540m.