(L.M. Otero/Associated Press)

The Federal Aviation Administration said Friday that an advisory group reviewing restrictions on electronic devices aboard airplanes has not finished its work and needs more time to complete its recommendations.

As tablet computers and e-readers have proliferated among travelers, rules that they be powered down during takeoff and landing have faced mounting criticism from fliers and some officials.

The advisory group was expected to issue its recommendations this summer but now plans to deliver them in September.

The new timeline was first reported Friday by the Wall Street Journal. The Journal’s report said the panel’s draft recommendations call for relaxing the ban on personal devices, although those findings are not final and could change.

“The FAA recognizes consumers are intensely interested in the use of personal electronics aboard aircraft. That is why we tasked a government-industry group to examine the safety issues and the feasibility of changing the current restrictions,” spokeswoman Laura Brown said in an e-mail. “At the group’s request, the FAA has granted a two-month extension to complete the additional work necessary for the safety assessment. We will wait for the group to finish its work before we determine next steps.”

The panel was announced in August by the FAA to explore whether the use of some electronic devices aboard flights could be expanded. But the panel was not charged with examining the restrictions on cellphone use.

The Federal Communications Commission bans the use of cellphones during flights. The agency had considered lifting that prohibition before opting in 2007 to leave the rules in place.

Julius Genachowski, who stepped down as chairman of the FCC last month, wrote a letter last year urging the FAA to allow “greater use of tablets, e-readers and other portable electronic devices during flight, consistent with public safety.”

Sen. Claire McCaskill (D-Mo.), who has also pushed for easing the restrictions, praised the potential changes.

“It’s good to see the FAA may be on the verge of acknowledging what the traveling public has suspected for years — that current rules are arbitrary and lack real justification,” she said in a statement Friday.

Currently, passengers are not allowed to use electronic devices at the beginning and end of flights, a prohibition that predates the ubiquity of smartphones, tablets, e-readers and other digital devices. The ban will become more complicated as companies introduce wearable computing devices such as Google Glass and smart watches.

There have been several widely reported cases of passengers kicked off of flights or even arrested for refusing to turn off phones.

Relaxing the ban would be “a common-sense step in the right direction,” said Jot Carpenter, vice president for government affairs at CTIA, which represents wireless companies. “I’m glad to see the FAA is acknowledging the realities of the 21st-century economy.”

A study released last month by the Airline Passenger Experience Association and the Consumer Electronics Association found that 30 percent of passengers said they had accidentally left an electronic device on during a flight.

“It’s no secret that the use of personalized electronic devices in the aircraft often causes a problem,” said Corey Caldwell, spokeswoman for the Association of Flight Attendants.

She said that flight attendants constantly have to remind passengers about the rules and that sometimes passengers outright refuse to turn off their devices. When these situations escalate, flight delays may result, she said.

Lori Aratani and Debbi Wilgoren contributed to this report.