Sweden-based conference phones supplier Konftel recently signed an agreement with U.S. phone and headset dealer Hello Direct for the distribution of its products. Hello Direct began selling products from Konftel at the beginning of November.   This deal represents an expansion of Konftel's presence in the U.S. market, where it has had offices in Chicago for three years.   "The agreement is very valuable to us and we have high expectations that it will strengthen our brand on the American market," said Clarence Jacobson, sales director at Konftel, in a statement at the time of the announcement. "Hello Direct is a respected and significant dealer that is particular when they choose which products to include in their assortment."   Hello Direct officials expressed similar satisfaction regarding the deal, saying that the two companies have a great many synergies. For example, GN Netcom wireless headsets sold by Hello Direct are interoperable with Konftel's audio conferencers, providing a unified solution for customers.   Jacobson added: "Hello Direct has the right channels for reaching our target audience. Being exposed on its website and in its high-circulation catalogs presents major opportunities for increasing our sales volumes."