UPDATE 1-Air France pilots continue strike, shares fall

* Air France pilots continue strike for 4th day.

* Expects to run 65-70 pct of long-haul flights from Paris

* Air France KLM shares down around 2 percent.

(Writes through with detail, background)

PARIS, Nov 17 (Reuters) - Air France (AIRF.PA) pilots went on strike for a fourth consecutive day on Monday, in a dispute over the airline's retirement plans.

Air France said it expected to run between 65 and 70 percent of its long-haul flights from Paris on Monday, as a result of the strike.

The situation on its medium-haul network should remain unchanged, with around half of its flights operating.

The airline said it had kept passengers informed of latest developments and would re-route passengers onto other flights where necessary.

The strike started at 2300 GMT on Thursday last week and is due to last until midnight local time on Monday. It will likely cost the Air France 100 million euros ($126.9 million), Chairman Jean-Cyril Spinetta said on Thursday.

The strike was called over proposals to allow pilots to retire at 65 rather than the current final retirement age of 60, a measure being discussed in parliament as part of wider social security reforms.

The company and the government say the planned change would be voluntary and pilots would not be forced to work until 65, but unions believe it is the thin end of a wedge that will force staff to work longer or accept lower pensions.

Air France KLM shares were down 2.1 percent at 10.34 euros in mid-morning trade, underperforming a 1.5 percent fall in France's benchmark CAC-40 index .FCHI.

Air France is the French flag carrier network operated by Franco-Dutch airline group Air France-KLM. The French government has a stake of around 16 percent in Air France KLM.

(Reporting by Sudip Kar-Gupta; Editing by Hans Peters)