ST. LOUIS » Enterprise Holdings, the nation’s largest rental car company, plans to hire 11,000 new full-time workers by the middle of next year, the company told The Associated Press today.

The hiring is expected to be complete by July 31, and could boost the company’s workforce to more than 80,000, depending on attrition, company executive Marie Artim said. The suburban St. Louis-based company’s revenues have more than doubled over the past 10 years, from $6.9 billion in 2003 to $16 billion.

The company plans to hire nearly 8,500 for management trainee positions, including many recent college graduates. Others will be hired for positions in information technology, administration and support roles at the company headquarters in suburban St. Louis, and in branch stores.

In addition to the full-time jobs, Enterprise plans to hire 1,500 interns. Typically, about half of its interns eventually become full-time employees, company officials said.

Enterprise Holdings operates Enterprise Rent-A-Car, Alamo Rent A Car and National Car Rental. It is one of the nation’s largest private companies. Its overall fleet includes 1.3 million vehicles at 8,200 rental stores.

Artim, vice president of talent acquisition for Enterprise, said the new hires are needed because nearly 11,000 people were promoted or changed positions within the company over the past year. She said the company typically promotes almost strictly from within its own ranks, noting that CEO Pamela M. Nicholson began in an entry level position at Enterprise more than three decades ago.

"It’s just an exciting time," Artim said. "Being a family-owned, privately-held company has allowed us to think long-term and strategic."

Enterprise was founded in 1957 by Jack Taylor as Executive Leasing with a fleet of seven cars. He changed the name to Enterprise in 1969 to honor the World War II aircraft carrier he served on, the USS Enterprise.

The company grew quickly by developing a niche for neighborhood locations rather than airports, making it popular among those whose cars or trucks were in the shop for repair. Enterprise acquired Alamo and National in 2007.

Nicholson became the first person outside the Taylor family to lead the company in June. Jack Taylor and his son, Andrew, were the only previous CEOs before Nicholson was promoted from president and chief operating officer. Andrew Taylor remains as executive chairman.