Time Warner Cable finished second with the surveyed business customers (those with 500 or more employees) followed by AT&T and Comcast in third and fourth place, the 2009 survey said customers with data services including cable modems, DSL, T1, T3/DS3, Ethernet and frame-relay services.

Those surveyed ranked services generally provided over wired infrastructure, including cable and switching. and routing components. But the services are often underpin wireless services deployed by companies, including wireless LAN.

The survey measured six factors driving satisfaction: Sales representatives, customer service, billing, cost of service, offerings and promotions, and performance and reliability.

These data services would not typically be regarded as the main underpinnings of cellular wireless service, however, even though AT&T and Verizon have enormous cellular networks that are surveyed by J.D. Power in separate studies.

Of 4,252 business customers surveyed in January and April, some were also from medium, small and home-based businesses. J.D. Power did not indicate how many customers were included in each group.

Based on a 1,000-point scale, Verizon finished at 694, Time Warner at 677, AT&T at 666 and Comcast at 630. Other carriers were not mentioned. The average was 672.

For small and midsize business users, Optimum Business finished on top with 673; Cox Communications finished with 669; AT&T had 632; Verizon got 629; Comcast got 621; Tim Warner Cable got 598 and Qwest got 592. The average score was 627.

For home-based businesses, Optimum Business finished first at 654; Cox Communications had 637; Embarq had 629; Verizon had 626; Qwest had 625; AT&T had 617; Time Warner Cable had 589; Comcast had 570 and Charter had 535. The average was 601.

The average satisfaction score improved for small and mid size businesses by 27 points over the prior years survey and by 7 points for large businesses over the prior year, due to improvements in billing and customer service, J.D. Power said in a statement. Overall satisfaction had declined sharply from 2007 to 2008, J.D. Power said.

J.D. Power said the survey showed that communications problems between customer service reps and customers showed a sharp decline over the previous year, showing the impact of strong internal training programs. There also were no major differences in network outage performance between 2008 and 2009.

Verizon performed the highest for large businesses with high rankings in five of the six areas measured, except on billing. No further details were available, however.