Iraq's proven oil reserves have increased to 150 billion barrels, up from a previous figure of 143.1 billion barrels, oil ministry spokesman Assem Jihad said on Wednesday. "Thanks to the work of the ministry of oil and exploration contracts awarded to energy companies these past two years," Iraq now has reserves of 150 billion barrels of oil, Jihad told AFP. He added that the new figure would likely rise in future as further exploration work is done. Iraq had previously said it had proven reserves of 143.1 billion barrels of oil and 3.2 trillion cubic metres (111.9 trillion cubic feet) of gas, both of which are among the largest reserves in the world. Baghdad is almost entirely dependent on energy sales for much-needed revenues to rebuild Iraq's decrepit infrastructure and state-dominated economy, both of which have been shattered by decades of conflict and sanctions. It has sought in recent years to sign contracts with international energy firms in order to boost output sharply and cement its role as a key global oil supplier. Oil Minister Abdelkarim al-Luaybi said last month that Iraq plans to invest $173 billion in its energy infrastructure, including its gas production and storage facilities, over the next five years.