"Had our partner TDP cooperated with us during NDA tenure, there would have been separate Telangana," Advani said in his valedictory address at the Global Investors Meet here.
NDA government carved Uttarakhand, Chhattisgarh and Jharkhand out of Uttar Pradesh, Madhya Pradesh and Bihar, respectively, during its rule, he said.
"But, TDP did not extend support for formation of Telangana," the BJP veteran said.
Advani said Telangana issue is hanging in balance as Congress government at Centre was making "hollow" statements on its formation.
"There is uncertainty on whether Telangana will be created," he added.