Oil leaders' decision to decide against an output ceiling for the oil exporting countries is likely to dent the Federal Reserve's confidence for an interest rate hike. The Organisation of Petroleum Exporting Countries (Opec) said no to a maximum on 4 December in Vienna.

Between 15 and 16 December, the Federal Open Market Committee (FOMC) is holding its monetary policy meeting and the world is eagerly awaiting its decision on a rate hike. Despite global financial turmoil, an increase in the bank's interest rates is highly expected.

"Why should Opec alone sacrifice its part in the market?" Iraqi oil minister Adel Abdul Mahdi asked reporters after the cartel decided to keep its output at around 31.5 million barrels per day. "Americans don't have any ceiling, Russians don't have any ceiling, why should OPEC have a ceiling?" he said.

Oil price benchmarks plummeted to one of their lowest points in 2015 following the announcement, flirting with below-$40 (£26) levels. Ahead of the Opec meeting, an output ceiling was expected, causing oil prices to edge up slightly.

Reports had surfaced suggesting Saudi Arabia, the biggest crude producer, wanted to propose an agreement that would balance oil markets. This would mark the first Opec initiative to deal with the falling prices since the continuing downturn started in June 2014.

However, the cartel left petrol investors disappointed after Saudi's mention of the output limit angered Iranian officials. Iran is on the verge of reopening its tabs as implementation day, which will see economic sanctions lifted, is nearing. The P5+1 sanctions on Iran are expected to be lifted at the start of 2016.

Although it is expected to take months or even years before the sanctions are fully lifted and the effects have vanished, a production limit would be devastating for Iran's oil industry ahead of the implementation day.

Michael Every, market analyst at Rabobank, said in a morning note that the effects of the meeting outcome will be felt across monetary decision makers. "All central banks will have to accept that oil price declines are also likely to be 'too unlimited' given OPEC's failure to reach any production cut agreements on Friday," he said.

"It seems we are soon going to test the [Brent] lows seen in August. Getting inflation back up to target levels is going to prove tough against that backdrop, especially with Iranian oil likely to flow in greater volume in the near future."