Chennai, May 1 (IANS): Tamil actor Ajith Kumar was busy shooting for his upcoming untitled action-drama in Jaisalmer on his 42nd birthday Wednesday.

However, the film unit is planning to celebrate later in the evening along with Ajith's wife Shalini.

"Ajith sir will be busy shooting the climax of his film during the day. We have planned a small party in the evening. His wife Shalini, who has accompanied Ajith sir for the shoot, will join in," a source from the film's unit told IANS.

Ajith is wrapping up all pending work fast because he is due for a knee surgery Oct 21.

"He wants to complete all projects before be goes for his surgery; therefore, he is working on a tight schedule," he added.

The makers of the film launched a one-minute teaser Wednesday as a birthday gift for Ajith's fans.

Directed by Vishnuvardhan, the untitled film also features Arya, Nayanthara, Rana Daggubati, Nayantara, Taapsee Pannu, Kishore, Atul Kulkarni, Mahesh Manjrekar and Suma Ranganath in important roles.

Ajith has also begun working on another untitled Tamil film with director Siva. He has already finished 10 days of shoot for the film, which also features Tammannah Bhatia, Vidyullekha Raman and Manochitra.