As of 2:30 p.m. PST, the service was up and running again after repeated attempts to use the site were unsuccessful earlier. A Yahoo spokeswoman said the outage resulted from a downed telephone line in the Chicago area that affected its operations.
"Our apologies: We are experiencing technical difficulties and our stock quotes are not current. We are working to restore the service; please check back later today," the company said in a statement on the site during the outage.
Online stock quotation and financial services increasingly have come under fire by some consumers, who charge they are not reliable enough. The companies deny this, although some concede that improvements are necessary.
The criticism came to a head last October, when the Dow Jones Industrial average suffered its largest one-day point decline. Some of the online trading services were highly criticized because consumers charged they could not execute trades or get quotes on a timely basis.