ISTANBUL (Reuters) - Saudi Arabia's Energy Minister Khalid al-Falih will not attend meetings on Wednesday (Oct 12) between Opec and non-Opec countries in Istanbul but told Reuters he saw signs that countries outside Opec were willing to contribute to balancing the oil market.

"Tomorrow's meeting is a very informal consultative meeting between the countries that happened to be here," Falih told Reuters at the World Energy Congress in Istanbul.

"Unfortunately due to prior commitments I am leaving now so I will not be in the meeting but I will be following it from afar and I will be getting indications about what countries have agreed to," he said.

Opec officials are embarking on a flurry of meetings to nail down details of an agreement reached in Algiers last month on modest oil output cuts, the first such deal since 2008.

The chain of meetings, starting in Istanbul, signal that unlike in the first half of 2016, the group is more serious now about managing the global supply glut and propping up prices.

Falih said he had met with Russian Energy Minister Alexander Novak in Istanbul, and described the energy conference in the Turkish city as a "great step forward".

"From the meetings I have had on the sidelines of this conference today and yesterday ... it is quite clear that many countries are not only supportive of the Opec decision in Algiers but are enthusiastically willing to join," he said.

"We are not talking about support, we are talking about contribution in the direction we are seeking which is basically that we are going to attempt to speed up the balancing process that is already underway."

Falih said those efforts were not about the oil price itself, but about sending a signal to the oil industry to start investing again.

Oil prices have dropped sharply since mid-2014, forcing producers and companies alike to shelve projects and cut oil investments, raising worries over a future supply shock that could lead to a spike in prices.

Saudi Arabia, the world's top oil exporter, currently produces 10.6 million barrels per day and has a production capacity of 12.5 million bpd, leaving it able to boost output further to meet any global shortage.

But despite that significant potential, Falih said "we want the industry to always have some ... spare capacity so that we respond to any emergencies. To do that we need to start investing across the industry and across different regions."

"We are concerned that there is not enough new capacity coming for the next few years to meet the incremental demand that is back at healthy levels and also to offset whatever natural decline that has taken place," he said.

"What we want to see ... is a moderate level of capacity increases coming from across the industries."