Leading Tamil director Shankar has signed on Rajnikanth [Images], fresh from the stupendous success of his latest starrer Sivaji, for his next project titled Robot.

That of course should come as no surprise to Rediff readers -- we had reported on the possibilities a few days before the news became official.

Shankar has been toying with the casting of this film for years now. Initially, he considered Kamal Haasan [Images], but the Tamil superstar blotted his copybook with the box office fiasco Alavandaan (Abhay, in Hindi) and, simultaneously, had creative differences with a director who is very firm about what he wants.

Shankar moved on to other projects; in the background, however, he was engaged in negotations with Shah Rukh Khan [Images].

Khan had for long expressed a desire to work with Shankar, and at one point promised bulk dates. However, on this particular project, Khan reportedly did not quite see eye to eye with the director, who put the project back on the shelf.

Aamir Khan [Images] was next in line, but negotiations broke down at the preliminary stage itself though neither the star nor the director have revealed what the sticking point was.

Finally, Shankar has his male lead -- and the casting of Rajnikanth removes a lot of headaches. Firstly, any film starring the South's reigning superstar gets sold as soon as it is announced, and for whopping sums at that, so the director with a penchant for enormous budgets will have all the money he wants to play with.

Further, Shankar -- fresh from his successful collaboration with Rajni on Sivaji -- plans to make the film simultaneously in Tamil, Hindi, Telugu and possibly Malayalam, thus opening up more areas of the country to exploit. Early word is that while Shankar hasn't finished costing his film yet, it could prove to be among the top two or three most expensive films ever made in India.

By way of bonus, Shankar has roped in A R Rahman to score the music, teaming up with a composer who was a major factor in ensuring that Shankar's early films were superhits.

He is currently busy finalising the rest of the cast, and the technical crew. Of the movie itself, little is known; Shankar has a reputation for being close-mouthed about his subjects.

However, inside buzz on a project that has been in the planning stage for years now is that the storyline will feature a man who also, in the film, has a robotic avtaar; hi-tech special effects is believed to be a vital component of the film, and insiders say Shankar has for some time now been in discussions with various top professionals, both in India and abroad, and is on the verge of finalising the outfit that will provide the tech component.