UPDATE 1-Nexans sees first-half cable sales down 15 pct

* Nexans sees H1 cable sales down 15 pct

* Expects operating margin at 4.5-5 pct at June 30.

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PARIS, May 26 (Reuters) - Nexans (NEXS.PA) expects a 15 percent drop in comparable cable sales in the first half but its performance should improve in the second half, helped by energy demand and lower costs, the world's biggest cable group said on Tuesday.

The group maintained its 6 percent operating margin target for the year but should reach between 4.5 percent and 5 percent at June 30, it added.

"A favourable seasonal pickup in energy infrastructures, the end of the destocking phenomenon as well as the first effects of the cost reduction measures ... should positively contribute to the performance of the second-half of the year," it said in a statement.

Separately, Frederic Vincent, the group's new chief executive, told Les Echos newspaper in an interview published that Nexans was still looking for long-term investors to stabilise its shareholder base.

"The presence of one, two or three major shareholders would not be a bad thing," he told the daily. "We cannot constantly live with a very volatile shareholder base."

Vincent had already said in early March, when he was chief operating officer, that the group would welcome the arrival of another stable long-term investor with a 10 to 15 percent stake. (Reporting by Astrid Wendlandt; Editing by David Holmes)