Davis, principal conductor of the LSO since 1995, will become president of the self-governing orchestra.
In addition to his artistic and general director posts at the Mariinsky, Gergiev holds the positions of principal guest conductor of the Metropolitan Opera and music director of the Rotterdam Philharmonic, and also runs the Stars of the White Nights festival in St. Petersburg, the Moscow Easter Festival, the Gergiev Festival Rotterdam, and the Mikkeli International Festival in Finland.
Gergiev has agreed to an initial three-year term at the LSO, beginning in January 2007. He will conduct the orchestra in 12 programs a year at the Barbican Centre as well as leading the orchestra on tour.
"I remember with excitement my London debut as a young conductor...seventeen years ago this month," Gergiev said. "In the meantime I have led many concerts here with my own orchestra and opera company and I have happily conducted many orchestras around the world, but uniquely I have felt a special relationship developing between the LSO musicians and me."
Davis, in his newly created position, will spend 10 weeks a year with the LSO, according to a statement. It was not immediately clear what his responsibilities will be. The LSO's primary administrator is the managing director, a post held for the last two decades by Clive Gillinson. Gillinson leaves this summer to become director of Carnegie Hall, and will be replaced by Kathryn McDowell, currently director of the City of London Festival.