Goldman Sachs says the next battle for technology companies will be fought in Indonesia, because of the South-east Asian country's huge population, high economic growth and "untapped market potential".

In a report that the brokerage describes as the "first of its kind", analysts led by Mr Koh Miang Chuen looked at the two sectors that they believe offer the biggest opportunities for profits - gaming and e-commerce - and took a bottom-up approach to determine the size of the market.

It says gaming revenue could have a compounded annual growth rate (CAGR) of 22 per cent over the next five years, while gross merchandise value in e-commerce could see a CAGR of 61 per cent.

Goldman says some of the biggest names in the technology industry have made large investments in Indonesia in the last few years.

It cites SoftBank Group, Alibaba, Tencent and Alphabet's Google.

For example, SoftBank was part of a group that invested US$100 million (S$130 million) in Internet shopping hub Tokopedia in 2014. It also teamed up with Didi Chuxing to invest US$2 billion in Grab, which has just bought Uber's business in South-east Asia.

But those companies are not the ones that the brokerage is recommending buying - at least not in this report.

The best way to play this? Buy the ADRs (advanced depository receipts) of a Singapore-based Internet company called Sea. Sea is the parent of Indonesia's Garena (a digital entertainment business) and e-commerce platform Shopee.

Sea is well positioned to benefit from Indonesia's growth prospects, trends and competitions, the Goldman report says.

Sea's ADRs have fallen 30 per cent since they were listed last year. Despite that, there are no analyst bears.

The company has nine "buy" ratings, and analysts expect the ADRs to rise 76 per cent over the next 12 months. Goldman is even more bullish: It reckons they will double.

BLOOMBERG