* Communications agency looking into looser rules on mobile phone use
* DOT has heard outpouring of opposition to in-flight phone calls
* U.S. regulations lagging those in some European countries
WASHINGTON, Dec 12 (Reuters) - The U.S. Department of Transportation said on Thursday it might ban the use of cellphone calls by passengers during flights, even as the nation's communications regulator voted to consider loosening rules that now ban connecting to wireless services onboard aircraft.
The competing efforts by the two agencies could result in a middle ground, under which passengers may before long be able to use their mobile phones to text and surf the Internet, but not make phone calls.
In a 3-2 vote, the Federal Communications Commission's Republican commissioners dissented from their three Democratic colleagues in opting to initiate a review.
All five commissioners expressed reservations about the negative social implications of allowing phone calls during flights - and any move in that direction seems likely to be stymied anyway by the transportation department.
"Over the past few weeks, we have heard of concerns raised by airlines, travelers, flight attendants, members of Congress and others who are all troubled over the idea of passengers talking on cell phones in flight - and I am concerned about this possibility as well," Transportation Secretary Anthony Foxx said in a statement.
"USDOT will now begin a process that will look at the possibility of banning these in-flight calls," Foxx said.
A majority of the flying public is said to dislike the prospect of in-flight phone calls - especially those made by somebody else.
FCC Chairman Tom Wheeler termed Thursday's move merely "the beginning of a process" to seek input, and said he was sympathetic to those who opposed any step toward in-flight mobile phone use.
"I get it. I don't want the person in the seat next to me yapping at 35,000 feet any more than anyone else," Wheeler said.
The FCC's proposal would leave it up to airlines to decide whether to allow passengers to use their own wireless data and call services.
Wheeler, in statements and in an essay published in USA Today on Thursday, termed the FCC's proposal purely technical and would give airlines the flexibility, but not a mandate, to use the latest technology.
"The proposed new rules maintain the ban on cellular service in-flight on planes unless the aircraft is equipped with new specialized onboard equipment," Wheeler wrote.
At a Congressional hearing, Wheeler said the FCC was "proposing to continue the ban on mobile devices that can interfere with terrestrial networks. But where there's new onboard technologies that eliminates that potential for interference, then there's no need for an interference rule. This is the responsible thing to do."
The FCC's proposal has launched a heated debate over the social implications of letting passengers chatter during flights.
A Quinnipiac University national poll released on Thursday found 59 percent of American voters opposed the use of cell phones on airlines, while 30 percent were in support.
Some carriers, such as Delta Air Lines, have said they would not let fliers use cell phones in flight even if regulators allow it, and several lawmakers have introduced bills to block in-flight phone calls.
"Historically our research data has told us that customers and our flight attendants feel voice calls will negatively impact the onboard experience," Delta spokesman Paul Skrbec said in a statement.
The FCC's review has been under way for years, as the technology has advanced and made the restrictions - driven by concerns about interference to wireless networks on the ground - outdated.
"The commission correctly determined the first necessary step is to investigate whether or not it is technically feasible to operate devices without causing harmful interference to avionics or to wireless networks," said Scott Bergmann, vice president of regulatory affairs at wireless association CTIA.
Some airlines in Europe, the Middle East and Asia already allow in-flight mobile phone use. "The Commission believes that these systems can be successfully deployed in the United States," the FCC said.
Both the commission and the Transportation Department deliberations are expected to take some time and including the opportunity for public comment.
Some of the strongest opposition is expected to come from flight attendants.
"In far too many operational scenarios, passengers making phone calls could extend beyond a mere nuisance, creating risks that are far too great," said Veda Shook, president of the Association of Flight Attendants.