AUGUSTA — The state’s first virtual charter school is on track to open this fall after signing up 279 students, exceeding its 243-student enrollment threshold.

“It’s exciting,” Maine Connections Academy Principal Karl J. Francis told the Maine Charter School Commission on Tuesday. “We’re ready to go.”

Maine Connections Academy got an extension to meet enrollment targets after falling nearly 50 percent short of a June 1 deadline to enroll at least 243 students in grades 7-9 in order to open in the fall. Parent and board member Amy Linscott, who enrolled her two children, said it was a relief to hit the target.

“It feels good not having that hanging over our head,” Linscott said.

At virtual charter schools, students log in from home and get their lessons online. The school provides a computer and other materials.

Critics of virtual schools have questioned the quality of the education and how the local boards of those schools often outsource much of their management to out-of-state for-profit companies that are beholden to shareholders. Supporters say virtual schools are good for students who don’t “fit” at traditional schools, from top athletes who are in intense training, to students who have been bullied.

Parent Melissa Randall said she and her 14-year-old daughter, Orianna, are “very excited” about the school.

Until now, they had “home-schooled forever,” Randall said. When they received a flyer for Maine Connections Academy, they went to an informational session.

“We were impressed,” said Randall, of Blue Hill. Now that Orianna is enrolled in eighth grade, the school management company has been “phenomenal” to work with, answering questions and helping them get ready for school, she said.

“They have bent over backwards,” she said, noting that when Orianna’s school supplies arrived by mail, a petri dish was broken. “Within an hour they had another on the way.”

Orianna is already online, participating in quizzes and vocabulary lists.

“There isn’t a day that goes by where she isn’t saying she’s answered an email or answered a quiz bowl question,” Randall said. “This is a new adventure.”

Maine Connections is the state’s sixth charter school. The others, all brick-and-mortar schools, are Maine Academy of Natural Sciences in Fairfield; Cornville Regional Charter School; Baxter Academy of Technology and Science in Portland; Fiddlehead School for Arts & Sciences in Gray; and Harpswell Coastal Academy.

Nationwide, there were 2.1 million students enrolled in charter schools in 2011-12, and 5.6 percent of all public schools were charters, according to the U.S. Department of Education.

Maine Connections operates under Connections Academy, a for-profit company that runs virtual charter schools in more than 20 states. The company is owned by Pearson PLC in London, a multinational corporation that formulates standardized tests and publishes textbooks for many schools in the United States.

A 2012 Maine Sunday Telegram investigation of K12, the nation’s largest online education company, and Connections Education, the operator of Maine Connections, showed that Maine’s digital education policies were being shaped in ways that benefited the two companies, that the companies recruited board members in the state, and that their schools in other states had fared poorly in analyses of student achievement.

K12 operates Maine Virtual Academy, a virtual school that submitted an application for one of four remaining open spots for Maine charter schools, which are publicly funded but operate independently of public school districts.

Also Tuesday, charter commission Chairwoman Shelley Reed said two groups that filed a letter of intent to apply for a charter are withdrawing from the process. That leaves four possible schools vying for the four open spots.

By law, the state has a cap of 10 charter schools until 2021, and six charters already have been approved.

The schools that are withdrawing are the Maine International Charter School, a southern Maine-based high school with the International Baccalaureate program, and Snow Pond Arts Academy, a high school in Sidney for performing and arts education.

“We found it regrettable that they were withdrawing, because both were bringing something slightly different than what we have,” said Bob Kautz, the commission’s executive director.

Kautz said the people behind the International Charter School were in talks with the Biddeford School District to explore a partnership, but he didn’t know where those talks stood.

John Stadler, who proposed the International Charter School, confirmed earlier this summer that he has approached multiple public school districts about a possible partnership – particularly to tap into demand from foreign students – but has declined to comment on any specifics, saying those talks are ongoing.

The schools that still have applications pending are:

• Maine Virtual Academy, a virtual school that is applying for the third time. It withdrew its application the first year, and was rejected by the commission last spring. The local board intends to contract with Virginia-based K12 Inc. for school services.

• All of ME Academy, a kindergarten through fifth-grade school based in either Lewiston or Auburn.

• Inspire ME Academy, a York County-based school for fourth- through eighth-graders.

• Compass Academy of Science & Exploration, for kindergarten through fifth grade in Kennebunk.

“It’s possible to take (all) four, but that doesn’t mean all will be moving forward,” Reed told the commissioners. “We need to be making smart, wise decisions. … We need to really get thinking about paying special attention this time, thinking we could get to that full 10 – or not – this year.”

The commission had planned to go over end-of-year reports for several charter schools, but did not have all the necessary information at Tuesday’s meeting, Reed said. The final reports, which will include financial information and academic testing results, will be discussed and voted on at the commission’s Sept. 2 meeting.