FACTBOX-Details of Mexico's energy reform proposals

April 8 (Reuters) - Here are the main details of energy reform proposals sent to Mexico's Congress by President Felipe Calderon on Tuesday.

* If approved, the reforms would set up a new type of flexible incentive-based service contract across state oil monopoly Pemex's activities that would reward hired companies for efficient or well-performed work with a bonus payment but no share in oil discovered or produced. It stops short of allowing controversial risk-sharing alliances with companies.

* The contracts would apply to everything from oil drilling and refining to pipelines and storage. The government hopes the performance incentives will spur on new oil exploration and production projects and will mean the building of three new oil refineries in Mexico over the next 12 years.

* Under a complete rewrite of Pemex's legal framework, the bill also proposes adding four independent directors to its 11-strong board, increasing its operational and budgetary autonomy, and improving transparency and accountability.

* The changes would let Pemex keep more of its oil export revenues, which are taxed at over 50 percent. Officials say Pemex stands to be around $4 billion to $5 billion better off each year and should be fully responsible for its spending and budget in around 10 years.

* Pemex would issue debt certificates related to its performance for Mexicans to invest in. The "citizens' bonds" could eventually be traded.

* Pemex's taxation system would be gradually honed to introduce varying tax rates for different types of oil and gas field.

* Regulation of the energy sector would be beefed up.

* Because it does not seek changes to the Constitution, the reform proposal could be passed with the backing of just 50 percent of Congress plus one vote. (Reporting by Catherine Bremer; Editing by Kieran Murray)