Iraq signed a $128-million gas pipeline deal Tuesday and issued a tender to develop an oilfield in the south with proven reserves of more than four billion barrels, the latest steps in its efforts to ramp up output.

The pipeline deal signed on Tuesday with South Korea's KOGAS is one of several to boost the country's long-neglected energy infrastructure, often seen as a bottleneck when it comes to raising oil exports, which comprise the lion's share of Iraq's economy and government revenues.

It involves constructing two pipelines over 22 months to transport dry natural gas and liquefied gas between fields in the northern city of Kirkuk and the Baiji refinery, officials at a signing ceremony in Baghdad.

Iraq also put out a tender to foreign firms for the development of the Nasiriyah oilfield, which has proven reserves of more than four billion barrels of oil.

The tender calls for a contract to be awarded by the end of next year for the development of the field and the construction and operation of a new 300,000 barrel per day (bpd) refinery.

Iraq currently produces around 3.4 million bpd and exports about 2.6 million bpd, but is looking to raise that figure dramatically in the coming years as several massive fields begin ramping up output.

But pipeline and export infrastructure remains lacking, after decades of underinvestment as a result of conflict and sanctions.

Iraq has 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 in the world.