Two of India's biggest film stars – one an ageing icon, the other the heart throb of a young generation – are fighting a battle for popularity, their rivalry revealed by subtle digs.

Amitabh Bachchan is 64, a veteran who has ruled the box office for decades and is still hugely popular. Shah Rukh Khan, 41, is the reigning star and believed to be Bollywood's highest-paid actor with a massive fan following.

For years, India's celebrity-obsessed media has compared their acting, star power, fan following and box office fortunes but Bachchan and Khan avoided commenting on each other, cloaking their rivalry behind studied sophistication.

But that seems to be history after Khan took over a popular television quiz show in January that Bachchan once hosted with unprecedented success. Since then, the two are taking veiled potshots at each other but, at the same time, attributing talk of their competition to the fertile imagination of a ravenous media.

"That was your generation, this is mine," Khan said in a TV interview when asked about Bachchan and the rivalry.

"I am quite good at what I do," added Khan, whose boyish charm and screen energy has won him millions of fans, especially among teenagers and children.

"I'm cool, hip, sexy and wonderful." Khan was apparently retorting to a remark by Bachchan that comparisons with a younger star only inspired him to act better so that Khan could imitate him.

Bachchan says comparisons are unfair as he is much older. "If you want to do an honest comparison, you should wait for him to get to 65 and then see how he fares with the box office king at that point in time," Bachchan told a news television.

While fans appear divided on who is a better host of the show, viewership ratings after a week of the quiz indicate audience interest in watching Khan may just be flagging.

Last year, the media got another opportunity to whip up the rivalry debate when Khan starred in a remake of a 1978 Bachchan film. Don, in which Khan portrayed a Mumbai crime boss three decades after Bachchan did the same, was a moderate success that could not replicate the cult status of the older version.

Comparisons also stretch to the celebrity endorsement pie with firms spending an average of about Rs 30.5 million a month on advertisements featuring the older star, just ahead of Khan's Rs 30.15 million, the India Today news magazine calculates.

Media reports say the rivalry has not only split the film industry – with producers and directors now belonging to either camp – but also divided loyalties among India's influential, from industrialists to politicians.

"Call it the clash of titans or the confrontation of generations, but it is a stealth war being fought with iron wills, velvet gloves and steel-edged smiles," India Today said in a recent cover story on Bachchan and Khan.

Both actors say talk of their rivalry is a media creation, but commentators say the controversy won't hurt either star.

"What this so-called rivalry has done has kept both actors in public memory," said Derek Bose, a Bollywood scholar.