Complex sentence: It was sold to Chung Kong Infrastructure Holdings Limited in 2004, and to HSBC in 2011, becoming part of South Staffordshire Water in 2013.
Split into simpler sentences: It was sold to Chung Kong Infrastructure Holdings Limited (CKI) in 2004, but was sold on to HSBC in 2011. It became part of South Staffordshire Water in 2013.