Marconi decided to focus on the then-booming telecoms sector, but acquisitions made during the dot-com bubble took a heavy toll on the company following the "burst of the dot-com bubble" in 2000/2001. On 19 May 2003, Marconi plc underwent a major restructuring into Marconi Corporation plc. In 2005, the company failed to secure any part of BT's 21st Century Network (21CN) programme, which sent the company's shares tumbling. The majority of Marconi Corporation's businesses (including Marconi Communications) were sold to Ericsson in 2005, and the remainder renamed Telent plc. On 27 October 2006, the company wound up voluntarily.