ATHENS, Greece (AP) _ Above the battered marble columns of the Parthenon a crane swings out, maneuvering a 10-ton block of masonry off the ancient temple for repair.

Greek conservation experts are partially dismantling the 2,300-year-old building on the Acropolis hill in central Athens to consolidate the city's best known ancient monument.

The folding, French-made crane installed inside the Parthenon earlier this year is a key piece of equipment in an ambitious 10-year restoration program mostly funded by the government.

''It speeds up the process of shifting the stones and it's very precise in replacing them,'' Manolis Korres, the architect in charge of the Acropolis restoration program, said in an interview.

''When it's not in use, it folds up behind the columns so the Parthenon outline isn't spoiled for photographers.''

Korres, who carried out architectural studies of the Parthenon for several years before starting to restore it in 1983, believes the ancient Greek temple-builders also used a crane, made of wood.

''We know such machinery existed,'' he said. ''Socrates the philosopher compared his nagging wife's voice to the creaking sound of a crane.''

The Parthenon, completed around 433 B.C. after 10 years of work, dominated the other temples on the flat-topped hill. It was dedicated to Athena, the Greek goddess of wisdom and patron of ancient Athens.

Pheidias designed its superb sculptures and a 39-foot ivory and gold statue of Athena that gleamed in the dim interior.

Two fires in antiquity, looting by Goths and Vandals, centuries of use as a cathedral and a mosque and a 17th-century explosion left the building a scarred shell.

In recent years, careless restoration, earthquakes and atmospheric pollution have caused more damage.

The $90,000 crane will lift down several hundred chunks of masonry so that restorers can fill in cracks and substitute non-corrosive titanium for rusting iron clamps inserted in the 1920s.

The iron rusted and expanded over the years, causing the marble to crack. Sulphurous rain seeped into cracks, dissolving the stone into soft plaster.

''The ancient masons knew better,'' said Nikos Toganides, the architect overseeing the crane operation. ''They sheathed the iron clamps in lead to prevent rusting. Tight fitting of the original blocks also helped stop weathering.''

Most of Pheidias' sculptures were taken off the Parthenon by the British diplomat Lord Elgin in the early 1800s when Athens was under Ottoman Turkish rule. They are now in the British Museum in London.

Conservators have removed the remainder, except for a section of blackened frieze high up on the western side of the temple showing young Athenians on horseback in a religious procession.

''We still have to decide whether the frieze can be safely removed without endangering the Parthenon's stability, or should be encased in a nitrogen- filled atmosphere to halt pollution damage,'' Toganides said.

Later this year, the 17-member conservation team will move a 34-foot column shifted by an earthquake a few inches back into place, he said.

The restorers also have identified and collected about 1,600 pieces of Parthenon marble that lay scattered around the Acropolis.

Many were fragments of blocks blown off the temple during a 1687 siege of Athens by Venetians. A shell landed right inside the building, exploding an ammunition dump used by the Ottoman defenders.

Eventually the restorers will replace about 2,000 pieces of masonry on the building, using new blocks cut near the ancient quarries on Mount Penteli outside Athens to fill in gaps.

''Deciding how much restoration to do raises philosophical and aesthetic problems,'' Korres said. ''We have the information to accurately reconstruct the whole temple, but that would be creating a new Parthenon.''

Too much restoration also would offend many of the 10,000 tourists who climb the Acropolis in summer expecting to see a familiar, pillared silhouette, he said.

Korres said his team regularly exchanges ideas on conservation methods with foreign experts ''because it's a developing field and we're restoring a unique monument that's important to everyone.''