SMRT has come under criticism in recent years after a series of train breakdowns led to public outcry in a country long known for an efficient and reliable public transport infrastructure.
The government said last week that it will buy almost S$1 billion worth of metro train assets from SMRT so that the country's main rail operator can focus on providing reliable and well-maintained services for commuters.
SMRT has said that the rail financing framework had become unsustainable and its rail fare margins had been on the decline as operating expenses had risen significantly due to maintenance regime and replacement programmes for the ageing network.
Temasek owns about 54 percent of SMRT, whose shares have been halted since Friday.
SMRT will become a wholly owned subsidiary of Temasek and will be delisted when the deal is completed.
Merrill Lynch is advising SMRT and Credit Suisse is advising Temasek.