Wales striker Bellamy has rejoined the Anfield club having been out of favour at City after spending last season on loan at hometown team Cardiff City in the Championship.
The 32-year-old has played for seven clubs, not including loan moves, and previously joined Liverpool in 2006.
Meireles has joined Chelsea on a four-year deal after Liverpool said on their website that the unsettled midfielder had handed in a transfer request.
The Portugal midfielder, 28, spent just over a season at Anfield where he made 44 appearances.
French forward Ngog has signed a three-year contract at Bolton with the 22-year-old having scored 19 goals for Liverpool since joining from Paris Saint-Germain in 2008.
Bolton manager Owen Coyle told his club's website: "He is quick, can score goals and knows what the Premier League is all about."
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