PORTICELLO, Italy Aug 23 (Reuters) - Italian emergency

services resumed their search on Friday for the body of Mike

Lynch's 18-year-old daughter, the only person still unaccounted

for since the British tech magnate's family yacht sank off

Sicily this week, killing him and six others.

The British-flagged Bayesian, a 56-metre-long (184-foot)

superyacht carrying 22 passengers and crew, was anchored off the

port of Porticello, near Palermo, when it capsized and sank on

Monday within minutes of being struck by a pre-dawn storm.

Lynch's daughter, Hannah, is presumed to be the seventh

victim of the shipwreck. An interior ministry official said on

Thursday her body might not be inside the yacht and could have

been swept out to sea.

A judicial investigation has been opened into the sinking,

which has baffled naval marine experts, who say a boat like the

Bayesian, built by Italian high-end yacht manufacturer Perini,

should have withstood the storm.

The CEO of The Italian Sea Group, which owns

Perini, told Reuters the shipwreck was the result of a string of

"indescribable, unreasonable errors" made by the crew, and ruled

out any design or construction failings.

Pulling the wreck out of the sea, where it is now lying on

its right side, apparently intact, at a depth of about 50 metres

(164 ft), may help investigators determine what happened to it,

but the operation is likely to be complex and costly.

Nick Sloane, the South African engineer who led the

operation to salvage the Costa Concordia cruise liner that sank

in 2012, said in Italian media interviews on Friday that the

operation would cost up to 15 million euros ($16.7 million).

He told La Repubblica newspaper the yacht's salvage would

have to be completed by mid-October, and take six to eight

weeks, including preparation work. Bringing the yacht to the

surface will have to be done "very, very slowly", and might take

a couple of days, he said.

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