Microsoft is weighing the investment of between $600 million and one billion dollars in Tele-Communications Incorporated (TCI), one of the largest cable television operators in the United States, the Wall Street Journal reported yesterday. The paper, citing people close to the companies, said the move would be part of a Microsoft drive "to influence the design of the new set-top boxes that will help bring the Internet to the nation's living rooms through cable wires". The software giant last June put one billion dollars into another cable firm, Comcast Corporation, in which it also acquired a 11.5 per cent equity stake.