Andrew Lloyd Webber is no longer the most influential person in UK theatre, according to The Stage newspaper.
Lloyd Webber sold four of his West End theatres last year
David Ian, who co-produced Guys and Dolls and The Producers, has replaced Lord Lloyd-Webber atop the Stage 100 list after five years.
Theatre owner Cameron Mackintosh, who produced Mary Poppins and My Fair Lady, is in second place.
Lord Lloyd-Webber shares third place with Ambassador Theatre Group founders Howard Panter and Rosemary Squire.
David Ian is global theatre chairman of US-based theatre operator Live Nation, previously known as Clear Channel Entertainment, whose productions were successful in London throughout 2005.
Stage editor Brian Attwood said: "This reflects the fact that, while this country remains the home of theatre, live drama is developing into a genuinely global industry."
WHO IS DAVID IAN?
Global theatre chairman, Live Nation
Live Nation is the largest theatre operating body in the UK
Its London theatres include the Apollo Victoria, Dominion and Lyceum
It also controls Manchester Opera House and Palace theatre, Liverpool Empire, Bristol Hippodrome and others
In 2005 David Ian co-produced Guys and Dolls and The Producers
His past production credits include Saturday Night Fever, Ain't Misbehavin' and Anything Goes
Originally starring Ewan McGregor, Guys and Dolls opened at the Piccadilly Theatre last June while The Producers - based on the Mel Brooks movie - also became a West End hit.
Cameron Mackintosh's West End production of Mary Poppins earned a best musical actress Olivier Award for Laura Michelle Kelly and is due to get a Broadway run in November.
Theatre impresario Lord Lloyd-Webber sold four of his West End theatres last year, using the proceeds to fund a £10m refurbishment programme for his eight remaining theatres.
Actor Kevin Spacey, now in his second season as artistic director of London's Old Vic, was ranked at number 14.
Edward Scissorhands choreographer Matthew Bourne was in 15th position while playwright Harold Pinter was at number 18 in the annual list.