* EU consultation papers show disputes over safety measures
* UN agency to consider steps to improve flight tracking
* Concerns over integrity of safety systems after MH370
PARIS, May 11 (Reuters) - The United Nations is leading a high-level effort this week to improve the way aircraft are tracked to address public concerns over the disappearance of a Malaysia Airlines passenger jet.
But the official response to missing Flight MH370 and a similar event in 2009 has already been clouded by rows between planemakers, airlines and pilots about costs and surveillance, new documents show, raising questions about how fast regulators can act.
Papers issued as a European agency toughened guidelines for black-box flight recorders last week show disputes about the economic and safety benefits, as manufacturers urged delay and pilots resisted pressure for more cockpit monitoring.
The European consultation process on black-box design is the latest case study of the conflicting interests that can arise whenever aviation safety is discussed internationally.
Experts say some of the same issues will be on regulators' minds when the U.N.'s International Civil Aviation Organization meets this week to discuss flight tracking - an issue which has seen limited progress since the loss of Air France Flight 447 in 2009.
Tracking and black-box recovery are inter-dependent because poor tracking can increase the time and costs for recovery.
"Safety is not something you can argue against, but airlines have a healthy distrust of regulators and if they don't see the cost/benefit arguments that are put forward making sense, they will say so," said aviation safety consultant Paul Hayes.
"On the other hand, the people who build equipment want to be certain there is market for it and they usually want a common standard to ... reduce their costs," said Hayes, director of safety at UK-based consultancy Flightglobal Ascend.
A case in point is the European Aviation Safety Agency's proposal last week to increase the maximum amount of recording time on cockpit voice recorders to 20 hours from two hours.
Flight MH370 is suspected of crashing in the Indian Ocean up to seven hours after it went missing on March 8, meaning it may never be possible to hear what happened at a crucial point.
According to the documents, Airbus questioned why Europe should go out on a limb after the United States reaffirmed the two-hour rule four years earlier.
It urged EASA to postpone until regulators could agree a common plan, expected in 2015/16.
Rival Boeing raised concerns that disjointed regulations could impose "significant cost" for manufacturers and airlines.
EASA responded its job was to uphold safety in Europe, not necessarily to fit in with decisions taken elsewhere.
Asked about this, an Airbus spokesman said: "Our first priority is always safety. We continually make proposals to certification authorities to improve safety at a global level."
A Boeing spokesman said: "Safety is always our number one priority and requires an industry-wide approach".
The increased voice recording time, set at 15 hours and later raised to 20 hours, drew most criticism from the pilots.
Some pilots have expressed concerns about recordings, saying they could be misused by employers, released without their permission or used in court without their permission.
The European Cockpit Association (ECA), representing 38,000 pilots, told EASA the longer tapes would only worsen that risk.
"We are the only occupation that allows its private conversations to be recorded. A surgeon in an operating theatre can make mistakes but will never allow conversations to be taped there," ECA association president Nico Voorbach told Reuters.
"We want to help with investigations because it makes our passengers' and our own lives safer, but in the absence of stronger protections we question why we should have more of our privacy taken away."
EASA said such misuse was rare in Europe.
To the chagrin of pilots, the EU papers show the first signs that authorities and the industry are paying closer attention to the risk of misuse of systems by pilots.
Malaysian investigators suspect someone shut off data links before taking the Boeing 777 off course with 239 people on board. Pilot advocacy groups say there is no evidence for this.
The U.S. Federal Aviation Administration and Australia's Qantas Airways both urged EASA to ensure a possible new system to locate planes in distress would be hard to turn off.
EASA said MH370 had "highlighted that it was easy to de-activate the aircraft transponder" and disappear from radar.
Airlines generally backed the longer cockpit recordings but queried other changes, while Danish regulators asked EASA to consider the cost to airlines.
The International Air Transport Association said its airlines always work to prevent accidents.
(Editing by Sophie Hares)