Prosecutors on Thursday accused Mansor of soliciting and receiving 189m ringgit ($45.12m at current exchange rate) in bribes from a company pitching for a government project.
She pleaded not guilty to both the charges.
Prosecutors said the payments concerned a 1.25bn ringgit ($298.4m) solar project in schools in the eastern state of Sarawak, on the island of Borneo.
Mansor, who was criticised for years for her extravagant lifestyle, is at the centre of a wide-ranging corruption investigation launched in May after Najib lost office.
Najib has since been charged with more than 30 counts of money laundering and abuse of power, mostly in relation to the 1Malaysia Development Berhad (1MDB) investment fund.
In October, Mansor was charged with 17 counts, including money laundering. She denied all the charges.
Earlier in July, police seized bags of cash, luxury purses, watches and other items estimated at $273m from premises linked to the former prime minister.
It took three days, six cash counting machines and 22 officials from the central bank to count the cash recovered from the premises, said the head of Malaysia’s commercial crime division, Datuk Seri Amar Singh, at the time.
“We couldn’t do the counting at the premises because the numbers were too huge,” Singh had said, adding that the seizures were the biggest in Malaysian history.