Nigeria, the world's eighth biggest oil exporter, is trimming supplies from October 1 after discussions with fellow OPEC members on how to stem a price fall, a senior Nigerian oil industry source said on Thursday.

Oil's drop from $78.40 for U.S. oil in mid-July to under $60 earlier this week prompted Edmund Daukoru, OPEC's president and Nigeria's top oil official, to say on Tuesday that something needs to be done to steady the price.

Nigeria will cut by 5 percent from October 1 because of the unofficial discussions between OPEC members, the source said, asking not to be named.

The source said leading OPEC producer Saudi Arabia and core Gulf member Kuwait were also involved in an informal pact to trim supply, but this has not been confirmed by either country.

A Gulf oil source said Kuwait's oil production was steady and there had been no order yet to cut supply. Saudi oil officials could not be reached for immediate comment.

OPEC's headquarters in Vienna was unaware of any production cuts being agreed.

I cannot confirm this to you because we are not aware. We have not been formally notified, OPEC spokesman Omar Farouk Ibrahim said.

A senior OPEC delegate would only confirm that consultations had taken place as prices fell.

After the steady decline of oil prices during the last week, there were a lot of consultations among OPEC members regarding the market and the necessary action to be taken, the delegate said.

Many members of the exporter group have been pumping near full tilt most of this year, ignoring quotas, as prices soared to record levels near $80 per barrel.

But a 20 percent drop in prices in two months to around $60 this week has many members worried, in particular Nigeria.

Nigeria is currently supplying 2.4 million barrels per day (bpd) to the world market, so the reduction of 120,000 bpd would bring its output down to about 2.28 million bpd, the Nigerian industry source said.

Nigeria's formal OPEC quota is 2.306 million barrels per day.

Saudi Arabia has been producing up to 9.2 million bpd this month, but Oil Minister Ali al-Naimi has stressed that figure was not final.

Oil consultant Petrologistics said preliminary data show Saudi Arabia pumped around 9 million bpd in the first half of September compared to 9.25 million bpd in the whole of August.