The engagement took place at Prajith's home in Moovattupuzha, Cochin, in a private ceremony.
Only close family members were invited.
Prajith Kartha is the son of Padmanabhan Kartha and Geetha. He is a businessman, settled in Bahrain.
Mamta was born and brought up in Bahrain, into a well-off Malayali family, which originally
hails from Kannur.
Mamta has worked in Malayalam, Telugu and Tamil cinema, and has done a Kannada film as well.
Mamta made her entry into films with Hariharan's Mayookham. Though the film didn't fare well at the box office, she soon became a sensation and found success in Tamil and Telugu films.
She was detected with Hodgkin's lymphoma, but survived the cancer.
She is a trained carnatic singer, and has done playback singing in Tamil and Telugu movies.
Prajith and Mamta were neighbours in Bahrain.
The couple will get married on December 28, in Kozhikkode, Kerala.