FACTBOX-What are the mayor's powers?

LONDON (Reuters) - London Mayor Ken Livingstone is seeking a third term in office when the capital votes on Thursday, May 1.

Here is a guide to the position of mayor:

* The mayor is head of London's government, with an 11.3 billion pounds budget to run public transport, police and fire services and promote the capital's economy.

* He or she makes London-wide policies on transport, planning, policing, culture, the environment and economic development.

* The official role is described as doing "anything that will promote economic and social development and environmental improvement in London".

* The mayor sets the annual budget and appoints all or some of the boards of public bodies including the Metropolitan Police Authority, the London Fire and Emergency Planning Authority and Transport for London.

* The mayor gives the go ahead to major building projects and manages Trafalgar Square and Parliament Square Garden.

* The office is not responsible for council housing, schools, social services, hospitals and street cleaning.

* The annual salary is 137,579 pounds. It is agreed by the London Assembly, with advice from the Cabinet Office.