With rising passenger numbers and congested facilities, Asia's airport market presents opportunities for investors, according to a DBS Insight SparX report. Airports of Thailand and Malaysia Airports Holdings are two airport plays for which DBS analysts have a 'buy' rating, alongside Beijing Capital International Airport.

Air passenger traffic in the Asia Pacific is expected to grow at a 20-year compound annual growth rate of 5.1 per cent from 2016, reaching 3.5 billion passengers in 2036. In Asean in particular, low cost carriers have been a huge catalyst for growth, with seat capacity quadrupling from 50.3 million in 2007 to about 222.9 million in 2016. In the same period, Asean also saw a 76 per cent jump in international arrivals from 62 million to 109 million.

Yet 12 of Asia's top 20 airports were already operating at or above capacity in 2017, with another four operating at 90 per cent of capacity or more. In Asean, Bangkok and Manila's main airports are operating above capacity, while Jakarta is nearing full capacity.

DBS estimates that some US$516 billion will be needed for investment in Asia's airports in the next two decades.

Though airport investment was traditionally the domain of the public centre, private capital is expected to play a larger role, with more privatisation opportunities surfacing in markets such as Indonesia and the Philippines, as well as China, India, and Japan. Added DBS: "Price weakness for airports on upcoming expansion capex presents an opportunity for investors to accumulate on the cheap airports with growth potential, with throughput growth proving to be a critical share price driver in the long term."

Many Asean governments have plans for airport expansion. The DBS report notes, for instance, that airport development "is part of the Indonesian government's key strategies", with one of its nine priorities -- according to the Indonesia Investment Coordinating Board -- being to develop 15 new airports by 2019. The Philippines' Build Build Build programme, launched in 2017 for the next five years, includes six airport projects.

Thailand's key Bangkok Suvarnabhumi airport will be expanded to double its capacity by 2021, while initial plans for secondary airports at Chiangmai and Phuket have also been proposed. Vietnam's Master Plan to 2020 includes plans to upgrade and expand most of its 23 existing airports and potentially build new ones, with this to be funded by a mix of government spending, domestic and foreign investment, and development aid.