25 Canada Square, or Citigroup Centre 2, stands at and, alongside HSBC Tower (with which it was built in tandem), is the joint 4th-tallest building in the United Kingdom (behind The Shard, One Canada Square and Heron Tower). Designed by César Pelli & Associates, construction of the 45-storey tower - undertaken by Canary Wharf Contractors - began in 1998 and was completed in 2001, with Citigroup leasing the building from the outset. The building was bought by RBS in 2004 along with 5 Canada Square (leased to Bank of America) for $1.12 billion. Subsequently, on 2 July 2007, CGC2 was individually sold to a joint venture between Quinlan Private and PropInvest for £1 billion (US$2 billion). Citigroup pay £46.5 million a year in rent for the tower, generating a yield of 4.6% to the owners. The east facing side of 25 Canada Square up to level 40 is configured for use by tenants.