Indonesia's state-owned oil and gas firm PT Pertamina expects its net profit to rise by 12.79 percent to $3.44 billion next year as the revenue from downstream and upstream business spheres pick up, a statement from the company said on Thursday.

Upstream business was expected to contribute more than 50 percent of the total business profits, boosted by a rise in production from existing fields and new fields obtained from merger or acquisition activities.

PT Pertamina expects to produce about 284,000 barrels of oil per day and 1,567 MMscfd (million standard cubic feet per day) gas or equivalent with 554,700 barrels of oil per day next year.

Besides, the hike of geothermal production to 3,036 GWh (gigawatt hours) also factored in the rise of production at the upstream sector.

In downstream business, the increase of profits was due to the hike of sales of non-subsidized fuel and business in the aviation industry.

In addition to the hike in sales, the aggressive marketing in petrochemical business and lubricant businesses also contributed.

In the gas business, PT Pertamina expected to benefit from the profound growth of the sector by 364 percent along with acceleration of the government's drive of shifting reliance on fossil fuels to abundant gas.

To bolster the target, the firm plans to set aside $7.85 billion capital expenditure next year, 48 percent of which will be allocated to upstream business and 22.2 percent for business development, 13.4 percent for gas business, 6.4 percent for processing business, 6.1 percent for mark, and 3.9 percent for petrochemical business and its subsidiary firms.

The company estimates that its income would grow 6 percent to $79 billion income next year with a $6.67 billion profit.

Southeast Asia's largest economy has tried to lure back judged investors to stimulate bearish investment in the oil sector as aging oil fields have pumped less crude oil.

At the same time, the country aims to reduce reliance on fossil fuels and to benefit more from its vast array of gas resources - the so-called oil to gas conversion program is expected to elevate efficiency and diminish air pollution.

Indonesia's proven oil reserve stands at 4 billion barrel, but the country's proven gas reserve is at 104.71 Tcf (trillion cubic feet), according to data from the energy and mineral resources ministry.

For this year, Indonesia estimates oil output is at 840,000 barrel per day and aims to ramp up the production to 870,000 barrel per day next year.