The commission agreed.

Had the commission ruled against AboveNet, the Canadian unit not only would have been regulated, it would have run up against this country's telecommunications foreign ownership restrictions.

The ruling may encourage more U.S.-based carriers to offer business services here. Among those supporting AboveNet's application to the commission were four U.S. business telecom providers with Canadian divisions: Verizon Business; Level 3 Communications LLC of Broomfield, Colo.; Cogent Communications Inc. of Washington D.C. and NextG Networks Inc. of San Jose, Calif.

Spokesmen for Verizon and Level 3 couldn't be reached for comment.

Canadian dark fiber owners could also benefit by having more buyers. One is Atria Networks of Markham, Ont. recently bought by Rogers Communications Inc.. A Rogers spokesman said no one from the company could comment Friday on the decision.