By Alkman Granitsas

ATHENS (Reuters) - After years of delays, legal wrangles and cost overruns, Greece hopes to open its Acropolis Museum by the end of 2007, Culture Minister George Voulgarakis said on Tuesday.

"It is our ambition that by 2007 the museum will be open to visitors," he told journalists after touring the half-finished building near the ancient hilltop temples of the Acropolis.

Greece had hoped to open the museum before the 2004 Olympics to push its claim for the return of the 5th-century BC Parthenon marbles, widely known as the Elgin marbles, from the British Museum.

But after decades on the drawing board, the museum is now three years behind schedule and, at a projected final cost of 129 million euros (89.3 million pounds), 25 percent over budget.

Construction was held up partly by the discovery of early Christian era ruins on the site. Another delay was caused by residents who challenged the construction of the museum, citing zoning laws in the city centre.

The building itself has faced engineering challenges. Because of the risk of earthquakes, the four-storey museum is built on 94 shock absorbing supports to allow it to sway during tremors.

Once it is finished, the museum will house artefacts from the temples of the Acropolis, including the Parthenon, as well as serving as a hoped-for future home for the disputed Elgin marbles.

Since independence in 1832, Greece has pressed Britain to return the sculpted blocks of the frieze that were cut from the Parthenon by Lord Elgin, the British ambassador to the Ottoman Empire, which occupied Greece at the time.

The frieze depicts a procession of horses and people through Athens during a festival and is a masterpiece of ancient Greece.

A brochure for the new Acropolis museum says "nearly half of the frieze is currently at the British Museum in London and its restitution is the object of major political struggles."