NEW ORLEANS (AP) — The state board that oversees Louisiana’s Superdome approved a contract Thursday for the first phase of a $450 million renovation of the 44-year-old New Orleans landmark that became a symbol of the city’s rebirth following Hurricane Katrina.

The unanimous vote by the Louisiana Stadium and Exposition District was to approve a $53 million contract for initial work on the stadium upgrade.

The renovations will be the most extensive since 2005, when the dome became a last-resort haven for thousands of Hurricane Katrina’s victims despite being heavily damaged. The upgrade is seen as a key element in getting a new long-term commitment from the Saints to keep the NFL franchise in New Orleans, and to attract future Super Bowls and other major events.

The state is to cover $90 million of the project cost. The Saints are to put up $150 million and the district is to pay $210 million.

Broadmoor LLC, a New Orleans area contractor, won the contract for the first-phase work that is to begin in January. The complete renovation is expected to take about four years to complete, with work planned around NFL seasons, major college football games and other major events, including the annual Essence Festival.

The dome has been the home of the New Orleans Saints since opening in 1975.

Included in the first phase of the upcoming renovation will be removal of some 80,000 square feet (7,430 square meters) of broad concrete ramps. That will make way for installation of new stairways and elevators.

Future changes include expanded, remodeled concourses and end-zone field-level seating.

The Superdome renovations are part of Gov. John Bel Edwards' efforts for a new state contract with the Saints aimed at keeping the team in New Orleans through 2015.