UPDATE 2-Air France-KLM beats forecasts with return to profit

* Operating profit 816 mln euros vs yr-ago loss 129 mln

* Reuters poll avg was for 2015 op profit of 544 mln euros

* Fuel bill declines 6.7 pct to 6.18 bln euros

* Plans further significant debt reduction this year (Adds nine-month share price high, details on fuel)

By James Regan and Cyril Altmeyer

PARIS, Feb 18 (Reuters) - Franco-Dutch airline Air France-KLM beat forecasts with a return to profit last year, helped by a drop in the fuel bill and growth in passenger numbers, lifting its shares close to a nine-month high on Thursday.

The carrier achieved an operating result of 816 million euros ($909 million), compared with a loss of 129 million in 2014, it said in a statement. This beat analysts’ average forecast of 544 million in a Reuters poll.

The company cautioned, however, that pressure on ticket prices from increased competition would eat into the benefits of cheaper fuel this year, though it maintained its medium-term financial targets.

“The global context in 2016 remains highly uncertain regarding fuel prices, the continuation of the overcapacity situation on several markets, and the geopolitical and economic context in which we operate,” the airline said.

“In consequence, the group expects the expected savings on the fuel bill to be significantly offset by unit revenue pressure and negative currency impacts.”

Air France-KLM is cutting labour costs and restructuring its network to better compete with deep-pocketed Gulf airlines and fast-growing European low-cost carriers. It has been helped by plunging oil prices, although the benefit was mitigated last year by pre-existing hedging contracts.

Air France-KLM also said it lowered its net debt to 4.3 billion euros at the end of December from 5.4 billion a year earlier and pledged a “further significant reduction” this year.

The airline forecast a cut of between 0.8 percent and 1.2 percent in unit costs in 2016, and free operating cash flow generation after disposals of between 600 million and 1.0 billion euros in 2016, against 606 million last year.

Shares in the company were up 9.6 percent by 0932 GMT at 8.162 euros, the highest since May and making the stock the leading gainer on the broad French SBF 120 index.

The carrier said the fall in oil prices cut its 2015 fuel bill by 6.7 percent to 6.18 billion euros, including a 20 percent decline in the fourth quarter. This could drop further to 4.5 billion this year.

The airline added the impact on revenue from the Nov. 13 Islamist attacks in Paris was estimated at 120 million euros in the fourth quarter. Three-month revenue nonetheless rose 2.2 percent to 6.3 billion euros.