ExxonMobil opened its Port Allen aviation engine lubricants plant to public officials and media Thursday and used the tour to do a little lobbying for a key state tax break for manufacturers.

The 90,000-square-foot jet oil plant that hit full production last year was part of $200 million in improvements at ExxonMobil's Port Allen lubricants campus and Baton Rouge chemical complex. The Port Allen plant employs 15 people, while the chemical plant expansion added 30 jobs. The projects helped support 400 construction jobs.

"One of the most important things I think that we can do from a property and sales tax standpoint is continue to build up the tax base in East Baton Rouge and West Baton Rouge (parishes)," said spokeswoman Stephanie Cargile. "All told we pay about $100 million annually in taxes here in Louisiana."

ExxonMobil's area plants employ more than 6,600 people, but the ripple effect on the economy means that one out of eight jobs in the area is supported by the plants and their workers, she said. Even regularly scheduled maintenance work at the plants have a big impact. Maintenance at the refinery supported a workforce of 1,600 with a payroll of $71.7 million during the first three months of the year.

The low cost of natural gas has created opportunities for ExxonMobil to invest in chemical facilities in Texas and Louisiana. However, the Baton Rouge facilities are competing against those in Texas for those dollars.

"The most important things we need are good infrastructure, a (skilled) workforce, a robust economy and a predictable tax base," Cargile said. "So one of the things that you'll hear ExxonMobil talking about is just making sure that our tax structure is predictable. "

Predictable and stable taxes are an important consideration when the company considers whether to bring a new project to the area, Cargile said.

The annual tour of an ExxonMobil facility took place less than two weeks after Together Baton Rouge, a faith-based activist group, announced plans to ramp up its lobbying efforts against the state's industrial tax exemption. The tax break allows manufacturers to avoid paying property taxes on new plants and expansions for up to 10 years. Together Baton Rouge hopes to convince the Metro Council, School Board and other public officials to stop giving manufacturers the tax break.

The group successfully lobbied state government to change the tax break, which it said has allowed East Baton Rouge corporations to avoid paying more than $1 billion in property taxes over the past two decades. Local governments must now approve the property tax breaks before the governor's office can award the incentives.

Follow Ted Griggs on Twitter, @tedgriggsbr.