Weeks after South Carolina’s top elected leaders announced a new expansion-driven incentives package for Boeing, they will join company executives at the 787 campus in North Charleston to celebrate the deal.

Gov. Nikki Haley, Lt. Gov. Glenn McConnell, House Speaker Bobby Harrell and Senate Finance Committee Chairman Hugh Leatherman are scheduled to attend the ceremonial bill signing today, as will Boeing’s lead attorney and its South Carolina general manager.

The bill, which was fast-tracked through the General Assembly and signed by Haley on April 23, gives Boeing $120 million in exchange for the company’s commitment to invest $1.1 billion and hire 2,000 more people in the state by 2021.

Today’s ceremony is not open to the public.

When Boeing announced in late 2009 that North Charleston would become the site of its first commercial aircraft assembly plant outside of Washington state, the company committed to invest $750 million and create 3,800 jobs in exchange for an incentives package The Post and Courier valued at as much as $900 million.

Having reached those goals, Boeing came back to the state this year to help finance its future expansion plans around Charleston International Airport.

Meanwhile, the Charleston County Council is on its way to approving its part of the latest incentive package, which includes allowing the company to pay less than a fifth of what its tax burden would otherwise be on its buildings, land and machinery over the next 30 years.

Today’s event will cap a week that saw Boeing reach its planned production rate of seven 787 Dreamliners per month between its dual Dreamliner factories in Everett, Wash., and North Charleston.

The first airplane built at that new rate rolled out this week, the company said Thursday. The plants are still on track to be making 10 Dreamliners a month by the end of the year, according to the company.

The ramp-up has continued on schedule despite the worldwide grounding of the high-tech jet for more than three months this year following a pair of mysterious smoky battery malfunctions.

Boeing’s North Charleston final assembly factory is building about two 787s per month and now features several completed jets on its flight line, soon to be delivered to customers like Air India and Hainan Airlines.

The plane maker has delivered 50 787s to eight airlines, and has more than 800 unfilled orders.