It's run for 21 years and taken £1.4bn. So why has its creator decided to put 'Cats' to sleep?

Cats was the Andrew Lloyd Webber musical written off even before it was first performed. Only the support of a then unknown producer called Cameron Mackintosh allowed the TS Eliot adaptation to see the light of day.

But yesterday it was announced that it will close – 21 years after it was first staged – as the most successful musical the world has ever seen, with 9,000 performances in London alone and global takings in excess of £1.4bn.

The show helped build the fortune with which Lord Lloyd-Webber has come to dominate popular theatre. So its passing – coupled with Saturday's final performance of another of his stalwarts, Starlight Express – has left London's Theatreland pondering one question: what do the next 21 years hold for Lord Lloyd-Webber?

His immediate plans, at least, are clear. Just one month after Cats shuts its doors, London's first Bollywood musical, produced though not written by Lord Lloyd-Webber, will premiere at the Apollo Victoria, until Saturday home for the last 18 years to Starlight Express.

With a desire for innovation for which he is not always credited, Lord Lloyd-Webber has assembled a team including the director Shekhar Kapur, who made the film Elizabeth with Cate Blanchett, the writer Meera Syal and the lyricist Don Black.

AR Rahman, the most famous composer in Indian film-making, was the starting point for the whole project. Marius de Vries, who produced the soundtrack to the film Moulin Rouge, which starred Nicole Kidman, will co-produce the album.

The personnel sound about as far removed from Elaine Paige and Michael Ball – more typical Lloyd Webber characters – as it is possible to get. Yet in its imagination and ambition it highlights an increasingly significant part of Lord Lloyd-Webber's work – as a man keen to develop new work and eager to take bright young talent under his wing.

Friends say that while Lord Lloyd-Webber's public image is of a composer of unchallenging popular tunes, Bombay Dreams is exactly the kind of innovative project, including new talent, that he has long been associated with.

A source said: "Although people might just see the shows running in London, the empire is constantly evolving."

His company, the Really Useful Group (RUG), is encouraged to develop other work in addition to Lord Lloyd-Webber's own. It backed the recent Pet Shop Boys musical, Closer to Heaven, which was certainly novel – if nothing else – according to most critics.

RUG tried, though failed, to recruit Sonia Friedman, the co-founder of the trendsetting company Out of Joint that has produced work such as Mark Ravenhill's Shopping and F***ing and Caryl Churchill's Blue Heart. Lord Lloyd-Webber's desire to woo Friedman suggests a desire to make a contribution to contemporary as well as popular theatre.

Further evidence for a change of tack was The Beautiful Game, his collaboration with Ben Elton. Both the subject – a love story set in Northern Ireland – and the box office performance – a £2.9m loss – support the argument that Lord Lloyd-Webber is doing anything but rest on his laurels.

To be fair, Cats was something of a revolution when it first appeared. Though now a staple of London tourism, it struggled to raise the original £450,000 production costs – even if investors have since received back 2,500 times their original stake.

Its success, contributing to Lord Lloyd-Webber's £400m fortune, has had many ramifications.

Really Useful Group has now expanded far beyond mere production with the acquisition of the Stoll Moss Theatre Group, making the company the West End's largest theatre proprietor. The portfolio features a string of theatres along Shaftesbury Avenue, including the London Palladium and the Theatre Royal, as well as the Drury Lane venue which Cats has transformed.

With such a powerful hand, Lord Lloyd-Webber is in a position to do something about the lot of the London theatregoer. His colleague Sir Cameron Mackintosh may have been more vocal about the dire conditions of London's ageing theatre stock and the appalling rubbish of the West End and its dire transport links. But Lord Lloyd-Webber has joined in many of the criticisms.

His friends claim that he is always writing and it would be a fool who rules out the prospect of another Lloyd Webber musical in the future, though there appears to be none in the pipeline for the immediate future.

And he certainly does not want his past work to be forgotten. The first compilation of his singles, performed by the likes of Madonna and Boyzone, has sold more than 1 million since December, even though it is yet to be released in America. A five-CD set of songs from all his musicals has also just been released and has topped the boxed-set album charts. The long-awaited film version of Phantom of the Opera is finally expected to get the green light this year.

Lloyd Webber shows, many of them produced by Cameron Mackintosh, are currently running in 18 productions from Australia to South Korea and Denmark to Japan, and have so far won him seven Tonys, seven Grammys, five Oliviers and a clutch of other honours.

They have contributed to the rise in the worldwide reputation of the British musical on a stage formerly dominated by the Americans.

The current cast of Cats was visited by Lord Lloyd-Webber and Sir Cameron Mackintosh on Monday night and told the news of its demise. They were, it seems, philosophical. Sir Cameron said yesterday: "They absolutely saw the sense of it." In the past couple of years, it has begun to struggle to break even, a problem exacerbated by the events of 11 September. With a feeling that this production had run its course, it was decided to close while it was still possible to go out on a high.

Cats has been a watershed in the life of everybody connected with it, Sir Cameron added. For Lord Lloyd-Webber, it was his first success independent of the lyricist Sir Tim Rice. For Trevor Nunn, dragged from the Royal Shakespeare Company to direct his first commercial venture, it was the first of a long run of successful musicals including Oklahoma! and My Fair Lady. For Sir Cameron, it provided freedom and financial independence, but the time was right to bring down the curtain.

"We thought long and hard about this. We know we owe so much to Cats – we will give it the greatest send-off ever," Sir Cameron said yesterday.

But Lord Lloyd-Webber, it seems, has already moved on to the next stage of his career, which may prove to be even more significant than the previous 21 years.