A plan to list Saudi Aramco in 2018 is on track, senior Saudi officials said in Moscow on Thursday, as Saudi Arabia gears up to sign a string of investment agreements with Russia.

The plan to float around 5 percent of Aramco in an initial public offering (IPO) is a centerpiece of Vision 2030, a wide-ranging reform plan to diversify the Saudi economy beyond oil which is being championed by Saudi Crown Prince Mohammad bin Salman.

"Work is ongoing to list Saudi Aramco in 2018," Aramco's Chief Executive Amin Nasser said at an energy forum in Moscow.

"We will be looking at (evaluating) investors as we continue to make progress related to timing and location."

Saudi Energy Minister Khalid al-Falih, who is also Aramco's chairman, said on Thursday that the IPO would happen in the second half of 2018, adding that the listing would be used as a "catalyst" for the opening up of the Saudi economy.

The announcement about the company's IPO will be made "in due course", he said while taking part in a panel discussion of an energy forum in Moscow.

Prince Mohammad has said the IPO, which could be the world's biggest, will value Aramco at a minimum of US$2 trillion and could raise as much as US$100 billion.

Money raised from the sale will be used to develop other sectors and industries in the country.

Aramco's listing is planned on Saudi Arabia’s local stock market plus at least one overseas exchange. New York, London and Hong Kong are the main contenders.

Nasser said the Saudi government would decide on the listing venue and that there were no current talks with Russian companies on them taking part in the IPO.

INVESTMENT DEALS

Both Falih and Nasser are part of an official Saudi visit to Moscow.

Saudi King Salman is in Russia on a state visit, the first to Moscow by a reigning Saudi monarch.

Several investment agreements will be signed during King Salman's trip and plans for a US$1-billion fund to invest in energy projects are likely to be finalised. These are part of efforts by two of the world's biggest oil producers to increase cooperation.

Russian Energy Minister Alexander Novak said on Wednesday Russia and Saudi Arabia would sign joint investment agreements worth more than US$3 billion during the visit.

One of those was a memorandum of understanding signed on Thursday between Aramco and Russia's oil trading company Litasco. Other similar agreements with Gazprom, Gazprom Neft, and Sibur will also be signed.

Nasser said Aramco was discussing several investment opportunities with Russian firms.

"LNG (liquefied natural gas) is one of the area where we are looking to collaborate with Russian partners," he said, giving an example of the MoUs that will be signed with Gazprom and Gazprom Neft.

The Russian Direct Investment Fund on Thursday will also sign an MoU with Aramco and Saudi's Public Investment Fund for investments in energy services and manufacturing.