Andrew Lloyd Webber and David Ian, the partners turned rivals behind the hugely successful television talent show How Do You Solve a Problem like Maria?, have been named the joint most influential figures in British theatre.

They top the annual list of the industry’s 100 most powerful individuals, to be published tomorrow in The Stage, the theatre and performing arts newspaper. And with both men preparing competing musical talent contests for transmission in 2007 their domination looks likely to continue.

Their BBC show, to find an actress to fill the Maria role made famous by Julie Andrews for a West End revival of The Sound of Music, was one of the television hits of the year.

Although some in the theatre world, including Equity, the actors’ union, criticised it for auditioning amateurs for a professional show, an audience of nearly eight million tuned in to watch Connie Fisher, a trained actress, win the Maria role in September.

Both men served as judges on the programme and received a significant boost to their public profiles, but the real benefit was to their businesses. When The Sound of Music opened to rapturous reviews two months later it had already registered £12 million in advance box-office takings, further enriching Lloyd Webber and Ian, the co-producers.

For Lloyd Webber, his nomination to the top spot marks a resumption of normal service after he dropped to third in the list 12 months ago after an “in-between year”. The established impresario, theatre owner and musical composer had previously led the list for five consecutive years.

Apart from The Sound of Music, in 2006 he put on an acclaimed revival of his musical Evita, discovered a new subject for a musical (Mikhail Bul- gakov’s satirical novel The Master and Margarita) and, perhaps most significantly, his Really Useful Group bought out Bridgepoint, the financier with which it co-owned its portfolio of West End musical houses.

Ian, a former jobbing actor once described as “like a demented East End footballer with a dodgy Bee Gees haircut”, is in first place for the second year running. He turned to producing in the 1990s and as the global president of production for the live events company Live Nation, now controls the biggest live entertainment portfolio in the world.

He said that he had been amazed by the success of How Do You Solve a Problem like Maria? “A lot of people had issues with it, but from my perspective, for the first time, a real synergy between TV and theatre was created. Where an entertaining TV programme had six to eight million viewers every week on Saturday night primetime, and I’ve got a show at the London Palladium with a £12 million box office advance with lots of Bectu, Equity and Musicians’ Union members employed for years, that’s a success. So I struggle to find a downside.”

In June he helped to launch a $35 million (£18 million) production of Lloyd Webber’s Phantom of the Opera in Las Vergas, said to be the most expensive musical theatre piece ever mounted.

However, by the end of the year cracks had appeared in their partnership, with Lloyd Webber complaining that Ian had held talks without him with the American channel NBC about a television show to find the star for a Broadway production of Grease.

The resulting show, You’re the One that I Want, is to be shown in the United States in January and a UK version is planned for ITV, produced by Simon Cowell’s company SyCo. Lloyd Webber will instead be involved with a rival BBC series Any Dream Will Do, to find a star for his musical Joseph and the Amazing Technicolor Dreamcoat.

£700m Lloyd Webber's estimated fortune

17 Musicals composed by Lloyd Webber

6 Tony Awards, 3 Grammy Awards, 5 Olivier Awards, a Golden Globe and an Oscar won by Lloyd Webber

3 Lloyd Webber's wives: Sarah Jane Tudor, Sarah brightman, Madeleine Gurdon

Source: Times database