Saudi Arabia's Oil Minister Ali Al-Naimi has said that the kingdom stood ready to "improve" prices but only if other producers outside of the Organisation of the Petroleum Exporting Countries (Opec) joined the effort.

Al-Naimi said Saudi Arabia had pumped around 10.3 million barrels per day (bpd) in March, marking an increase from previous months. He did not say why output had risen.

He also said he expected oil prices that have languished near six-year lows to improve in the near future.

Oil prices extended gains late on Tuesday as traders took Al-Naimi's comments as sign he may be open to renewed talks with producers like Russia and Mexico over curbing production in order to revive prices.

"The kingdom is still ready to help bring back stability to the market and improve prices in a reasonable and suitable manner, but with the participation of the main producing and exporting countries and based on clear principles and high transparency, so the kingdom or the Gulf countries or OPEC countries do not shoulder that alone," he said at a Saudi economics conference.

Opec agreed to maintain production at its meeting in November in spite of pressure to curb output and stabilize sliding prices and after discussions with Russia and Mexico ended without action.

Al-Naimi has taken a more open stance toward collaborating with big oil exporters outside of Opec in recent months, as oil prices fell much further than some members of the oil producer group had expected.

Al-Naimi also reiterated that Saudi Arabia was not competing with US shale oil, and took the chance to talk about the kingdom's own development of its shale natural gas resources.

He said: "I must clarify, conclusively, that the Kingdom of Saudi Arabia does not use oil for political purposes against any country, and it is not in a competition with shale or other high-cost oils. On the contrary, we welcome all new energy sources which add depth and stability to the market and that will help meet growing oil demand in the years to come."

Saudi expects to begin producing some 20 million to 50 million cubic feet per day of shale gas next year, rising to 500 million cfd by 2018, he said. The kingdom's has 300 trillion cubic feet of extractable natural gas reserves, he added.

Al-Naimi said aims to build an oil industry that can compete in all areas. "Our key objective is to ensure oil and gas can help boost the national economy and expand Saudi Arabia's industrial base.

"We aspire for the kingdom not only to be an oil producing nation, but also a global centre for the production of the materials and services needed by the oil, energy, petrochemical and other industries," he said. - Reuters