By Alina Selyukh and Karen Jacobs

WASHINGTON/ATLANTA, Nov 21 (Reuters) - The U.S. Federal Communications Commission is considering allowing airplane passengers to use their cellphones for calls and text messaging during flights, setting up a challenging debate over technical and social implications.

Last month, the Federal Aviation Administration said it would allow expanded use of electronic devices aboard planes, ending a long-standing ban. But the devices are still not allowed to connect to any ground networks and FCC rules have long banned the use of cellphones aboard.

The new proposal, to be voted on at the FCC's Dec. 12 meeting, would let the airlines decide whether to allow passengers to make phone calls, send texts or otherwise using their own wireless data and call services - although still not during takeoff or landing.

"Modern technologies can deliver mobile services in the air safely and reliably, and the time is right to review our outdated and restrictive rules," FCC Chairman Tom Wheeler said on Thursday in announcing that he has circulated the proposal.

But the battle could turn out to be a lengthy challenge as experts warn that passengers are not too welcoming of the prospect of listening to their neighbors chatter during flight.

Delta Air Lines, for instance, said on Thursday it would not allow cellphone use even if the FCC approves it, citing an "overwhelming sentiment" in customer feedback against voice calls in flight.

United Continental and Southwest Airlines also said their customers have expressed concerns about cellphone use during flight. Both carriers said they would study any changes the FCC might make.

"Passengers overwhelmingly reject cell phone use in the aircraft cabin," the Association of Flight Attendants-CWA union said, urging the FCC to not proceed with its proposal. The union expressed concerns that the conversations could be a distraction during emergencies and imperil safety.

Some experts also questioned whether the new rules would put a virtually impossible burden on flight attendants to ensure that cell phones are on but disconnected from the networks during takeoff and landing before the plane reaches 10,000 feet.

In fact, concerns about use of cellphones have already once killed a similar push at the FCC to relax its ban. The agency reviewed the matter from 2004 to 2007 - in the era predating the widespread use of smartphones and gadgets connected to wireless networks through providers such as AT&T Inc, Verizon Communications Inc or Sprint Corp.

The Telecommunications Industry Association, which represents makers and suppliers of communication networks, said it supported the FCC decision.