"If I was government of a country where my corporates trade a lot with one of these countries, and mediation is a value proposition, I'd think twice about not being inside.
"So I expect there to also be a strong second, third wave of parties coming on board to ratify."
During the ST interview, Mr Tong pointed out that mediation would be useful for companies and countries in terms of avoiding project disruption and achieving cost reductions.
It allows parties to retain their long-term relationship, he said.
"I've seen many cases where parties enjoyed a fairly long and relatively stable relationship and then sometimes when personnel change, they get involved in dispute. And that breaks the relationship that was not built overnight. That is one type of dispute that will benefit from mediation."
Another type would involve disputes in longstanding projects such as building infrastructure, power plants or a rail system.
Mediation would give the parties "the best chance" of not having the whole project abandoned, and prevent one discrete part of disagreement from derailing the entire process, he added.
Mr Tong acknowledged that the new convention cannot be enforced when a company from one signatory country mediates a dispute with a company from a non-signatory country.
"That is why we've been encouraging parties to get on board and sign the convention," he said.
He told the delegates at yesterday's forum that they play an important role in raising awareness of mediation, and in getting more countries to sign the convention.
He expressed confidence that more would come on board when they see the benefits of the new convention in action.
He also said in his address at the forum that much hard work and perseverance went into the establishment of the Singapore convention.
"It started off being quite difficult... there were many delegations, each with their own ideas and experiences on mediation, interests and perspectives on how enforcement should be achieved," he said.