Thailand's Chairman of the Senate Committee on Foreign Affairs, Senator Kraisak Choonhavan, has written a letter to Prime Minister Lee Hsien Loong and Speaker of Parliament Abdullah Tarmugi.
He has expressed concern over the potential effect on bilateral relations because of the acquisition of Shin Corp by Temasek Holdings.
The sale of Shin Corp caused massive protests in Thailand with many protesters calling for the resignation of Thai Prime Minister Thaksin Shinawatra over charges of corruption.
In Thailand, protestors have taken to the streets, claiming that the Thaksin family profited through legal loopholes to avoid paying tax.
In his letter to Mr Lee, Senator Kraisak Choonhavan stressed that the relationship between the two countries must not be jeopardised because of a single business transaction.
He said: "The relationship between our two countries must not be jeopardised as a result of a single business transaction, especially since Singapore is respected throughout the international community for her belief in the values of transparency, accountability and good governance."
In his reply on behalf of PM Lee, Singapore's Ambassador to Thailand, Peter Chan said the Republic shared the same concerns over the protests in Thailand.
And said that Singapore's stand is that Temasek and any other Singapore company that invests in Thailand must comply with Thai laws.
He added the government believed this is what Temasek is doing, and it does not expect any special exemptions.
Mr Chan said: "Temasek and any other Singapore company that invests in Thailand must comply with all Thai laws and regulations. That is what we believe Temasek is doing, and we do not expect any special exemptions or privileges for it."
In their replies, Mr Chan and Speaker Mr Abdullah both hoped that Singapore-Thailand relations will continue to strengthen. - CNA/ch