National Networks Ltd and the UK Post Office Corporation have severed their agreement, by which National re-sold spare telecommunications capacity on the Post Office’s internal network. The resale voice business was quietly switched to TRT Communications Inc last December. National was set up in 1989 specifically to sell the capacity, and the change leaves National’s attempt to become a public telecommunications operator in doubt. But the move strengthens the UK hand of Los Angeles-based IDB Communications. IDB which is in the process of purchasing TRT and bought Worldcom, another company that was awarded a provisional UK telecommunications licence late last year. Harold Burgess, finance director of the Post Office’s information technology division described the split from National Networks as very amicable, but said that since National had decided to concentrate on the value-added market, the capacity resale business, together with existing customers, were passed over to TRT. No one was available from National Networks for comment, but it is understood that the company will be building its own trunk network instead. The change in business leaves National Networks’application to the Department of Trade & Industry for a UK public telecommunication operators licence in the balance. When the company won its provisional licence last year it looked to be on the brink of success, but now the Department says that it is still considering how to move forward with the company on its application. Sources within TRT said it was considering whether apply for a licence of its own, but it is not certain that the company will actually need one: it may be able to operate under the Worldcom licence assuming that IDB’s acquisition goes through, TRT and Worldcom will share the same parent. IDB took over management of TRT from its present owner, PacifiCorp’s Pacific Telecom Inc on March 1 and says the deal will be finalised in the third quarter, once regulatory approvals are received.