Yahoo and British Telecommunications Thursday announced they are extending their partnership to offer consumers in the U.K. the option of making telephone calls over Yahoo's messaging product.The integrated call management product, called Yahoo Messenger with BT Communicator, will include VoIP services like PC-to-phone calling, Internet call waiting and directory lookup, bundled with instant messaging features, according to Yahoo U.K. spokeswoman Sue Jackson. The service will allow users to easily switch from instant message conversations to a telephone conversation, she said.Yahoo Messenger with BT Communicator will be made available for trial in May, Jackson said, and the product will be formally launched later in the year, though she declined to specify a date. The companies are in the midst of running trials of the product with both Yahoo and BT customers, Jackson said. So far, all indications from trial users are that they are happy with the quality of the telephone connections, she said. Quality has been a consistently problematic issue for VoIP services in general.Telephone calls made through the Yahoo\/BT product will be billed directly to the customer's home phone bill at normal toll-call rates. BT Communicator will be integrated into all Yahoo Messenger clients distributed in the U.K. and additional features will be added to the product in the future, BT and Yahoo said.Last June, Yahoo, of Sunnyvale, Calif., and BT, in London, teamed on an effort to increase DSL adoption by offering a joint Internet and broadband service to U.K. customers. Yahoo has similar partnership deals with U.S. telecommunication company SBC Communications and Canada's Rogers Cable.Yahoo has not made announcements about adding VoIP services to its products with SBC and Rogers, but Jackson did not rule out such possibilities in the near future. "What I can say is that we will not be making similar announcements today," she said.BT has been pushing hard to expand its broadband base in the U.K. with some success. Last month, the company announced its broadband and mobile services had been able to offset declines in its traditional voice business in its third-quarter 2003. Broadband, mobility and managed services, what BT calls its "new wave" offerings, rose 31% in the quarter to \u00a3838 million ($1.5 billion), while revenue from BT's traditional business fell 8%.BT has said it plans to sign up\u00a05 million broadband subscribers by the end of 2006. With that aim in mind, the company also announced on Thursday three other new broadband products: flexible bandwidth, BT Remote Management System and BT Rich Media, a set of tools for the creation and distribution of broadband content.