UPDATE 1-American Air says seats fixed on most 757s needing repair

(Updates number of repaired planes)

Oct 5 (Reuters) - American Airlines said on Friday it had repaired seat locks on 42 of 48 Boeing 757 jets after some seats came loose during flights this week.

The AMR unit, which filed for bankruptcy protection last year, said all 48 of its 757 jets that were to get the seat adjustments would be back in service by Saturday.

The carrier had canceled 94 flights over Thursday and Friday to improve the locking mechanisms used to secure seats to aircraft floors.

"We have identified the issue and our maintenance teams are securing an FAA (Federal Aviation Administration)-approved locking mechanism to make sure no seat can be dislodged," American spokeswoman Andrea Huguely said in a statement.

In recent days, three separate incidents occurred in which seats on American Airlines flights came unbolted from the floor, prompting an investigation by the FAA and jet inspections. American said an internal probe showed that improperly installed clamps had caused seats to loosen in six aircraft.

Fort Worth, Texas-based American Airlines has just over 100 757 planes, but only 48 use the seat model that has caused problems.

American Airlines and its pilots union resumed contract talks on Wednesday, but other problems continued at the bankrupt carrier this week.

A cockpit warning light caused an American flight to return to an airport shortly after takeoff on Tuesday, while a court said a union-organizing drive at the airline could go forward and flight delays brought more customer complaints.

(Reporting by Karen Jacobs in Atlanta; Editing by Gary Crosse,; Gerald E. McCormick and Dale Hudson)