LONDON (Reuters) - Publication of Libor interest rates that have become unreliable would be allowed for months but not years to ensure an orderly cessation, Britain's Financial Conduct Authority has said, ratcheting up pressure to ditch the tarnished benchmark.Banks were fined about $9 billion (£6.8 billion) for trying to rig Libor and ending its use is one of the biggest challenges the market is facing in decades.The London Interbank Offered Rate or Libor is used as a price reference across..