Water is a strategic asset and a matter of national security, so I was surprised to read that foreign buyers are considering a stake in Singapore's largest desalination plant (Foreign buyers eye Hyflux water plant; May 3).

Why should Singapore allow foreigners to own such a key national asset?

If the deal goes through, Hyflux will end up with only a minority stake of 30 per cent.

It should maintain controlling interest - at least 51 per cent - of Tuaspring if a divestment is to be considered at all.

We should take a leaf from Saudi Arabia's book: Even when Hyflux won the tender for the development of three desalination plants there, its job was to design, build, supply, test and commission them - not own and operate. The plants are to be handed over to the Saudi authorities upon completion, a reflection of their nature as strategically important infrastructure.

Desalination plants in Singapore may also be built on or near sensitive land, so that is another security consideration.

Ultimately, foreign buyers, as investors, may consider Tuaspring as merely an investment to be later sold off to another foreign entity for profit - with scant regard for its importance to us.

The report stated that regulatory approval for the deal is needed from national water agency PUB. As such a transaction could put our water security in jeopardy, I hope much thought will go into it.

Francis Cheng