LCI's recently appointed chairman Michael Beckett - brought on board in July to help turn the company's fortunes around - led the decision, having worked with long-term PR favourites College Hill in the past.
Beckett formerly worked as chairman of hotels group Queens Moat Houses - also a client of College Hill's.
Bell Pottinger previously worked with former LCI chairman Alan Goodenough, who resigned in July as the group's debts rocketed.
LCI's profits have been hit hard by a doomed 40 per cent investment in Las Vegas casino complex Aladdin, which is believed to have cost £826m to build, opened four months late and suffered a £140m cost overrun before filing for Chapter 11 bankruptcy.
The group is now hoping to sell its flagship St James casino for £55m to reduce its debts, which still stand at £320m despite a debt restructuring completed over the summer.
LCI owns five other casinos in London, two more in the UK and four abroad.
College Hill will handle all LCI's City comms, covering investor and analyst relations, financial calendar work and corporate PR. The agency reports to Beckett and LCI finance director Linda Lillis.