Microsoft, IBM and Ariba, which built a test version of the online directory last fall, plan to make the project available to the public later this month or in May.
The three companies last September proposed a Web standard and a new initiative that allows businesses to register in an online Yellow Pages that will help companies advertise their services, so they can find one another and conduct Web transactions.
The effort, which began with 36 supporters, has signed on about 130 companies, including Oracle, Intel, Hewlett-Packard, Sun Microsystems, Ford Motor and Nortel Networks.
The public test version of the directory, officially called Universal Description, Discovery and Integration (UDDI) Business Registry, is hosted on the Web sites of Microsoft, IBM and Ariba. Because the three companies' sites are connected, businesses will be able to register with the online directory by entering any of the Web sites.
Scott Cosby, manager of IBM's e-business marketing team, said several thousand businesses have registered with the directory to help test it out.
By year's end or early next year, other companies that support the project will host the registry, Cosby said.
"We're confident this will be something available globally and will have a profound impact on Web services," he said.