LAS VEGAS (AP) — The board over the Las Vegas Convention Center approved a nearly $60 million contract for a firm to design the center’s expansion.

The Las Vegas Convention and Visitors Authority board of directors signed off on the deal with Atlanta-based TVS Design on Tuesday.

The expansion is the second part of a $1.5 billion improvement project that was approved by the state Legislature last year.

The expansion includes a 600,000-square-foot (56,000-square-meter) exhibit hall that’s expected to open in 2021.

The firm will work with a team of Las Vegas designers and architects for the project.

Officials expect the expansion to generated an annual economic impact of more than $800 million and bring in more than 600,000 additional visitors each year.