By Andrea Shalal-Esa

DUBAI (Reuters) - The head of the Turkish air force said on Saturday his country's decision to buy a $3.4 billion missile defense system from a Chinese company was not final, and could still change.

General Akin Ozturk, commander of the Turkish Air Force, also said he did not see any linkage between Turkey's interest in buying F-35 fighter jets built by Lockheed Martin Corp (LMT) and the missile defense procurement process.

Asked at a global gathering of air chiefs about U.S. concerns that the Chinese system would not be interoperable with those of NATO members, Ozturk said, "This is not the last position of Turkey. It may change."

Ozturk told the Dubai International Air Chiefs Conference that he was not authorized to speak more broadly about Turkey's announcement in September that it planned to buy a missile defense system from a Chinese firm facing under U.S. sanctions.

Turkey announced in September it had chosen China's FD-2000 long-range air and missile defense system against rival offers from Franco/Italian Eurosam SAMP/T and Raytheon.

It said China offered the most competitive terms and would allow co-production in Turkey, but the decision caused alarm in NATO countries worried about China's growing clout.

Secretary of State John Kerry and other U.S. government officials raised concerns after Ankara's choice of the missile defense system built by China Precision Machinery Import and Export Corp, a firm that is under U.S. sanctions for violating the Iran, North Korea and Syria Nonproliferation Act.

Ozturk told Reuters after his speech at the conference that he did not see any link between a pending decision on Turkey's participation in the F-35 fighter program, involving Lockheed Martin Corp (LMT), and the missile procurement.

He said Turkey was poised to decided in December or January whether to proceed with an initial purchase of two F-35 fighter jets, but the exact date had not been set.

"I am very interested in the F-35," Ozturk told Reuters after his speech at the conference. "We have enough money." Turkey helped fund development of the F-35 and hopes its participation results in component orders for Turkish firms.

U.S. arms makers Raytheon Co (RTN) and Lockheed are considering ways to sweeten their offer to build a Patriot missile defense system for Turkey, two sources familiar with the issue told Reuters earlier this week.

Both sources said no decisions had been made and it was important to allow Turkey - a member of NATO - time to make up its mind.

One European defense official at the conference said Turkey's move had caught many NATO allies by surprise given concerns about the ability of the Chinese system to operate together with NATO members' missile defense systems.