FILE PHOTO: OPEC Secretary-General Mohammad Barkindo attends a session of the St. Petersburg International Economic Forum (SPIEF), Russia May 25, 2018. REUTERS/Sergei Karpukhin

BAKU (Reuters) - The global oil industry should ramp up investment to ensure it can cope with future consumption growth and avoid supply shortages, OPEC Secretary-General Mohammad Barkindo told a conference in Baku.

The Organization of the Petroleum Exporting Countries (OPEC) and other producers led by Russia last year began withholding 1.8 million barrels per day (bpd) of supplies to tighten the market and prop up prices that in 2016 fell to their lowest in more than a decade at less than $30 a barrel.

Both Russia and the OPEC leader Saudi Arabia have spoken about the need for a gradual increase in oil production as the goal of removing excessive oil stockpiles has now been achieved and the market has broadly been balanced.

“The next critical phase before of us in the whole process is to sustain this accomplishment of market rebalancing and gradual recovery in investments and the return of confidence in our industry,” Barkindo said.

“One of the greatest and most prescient challenges before us is ensuring that there will be adequate levels of investment in a predictable fashion.”

Barkindo said the pace of investment has picked up this year but there were not enough robust investments in long-cycle projects that are “the base load of future supply and the foundation of this industry’s future”.

He added that the required oil sector investment in the period to 2040 is estimated at about $10.5 trillion to meet future oil demand expected to surpass 111 million bpd.

“Every effort should be made to avoid a potential supply gap,” he added.