Members of the families that own Turkey’s two biggest groups of companies sold a combined total of about $575 million in shares in their respective groups, as the benchmark Turkish stock index closed at a record high on Wednesday.

The Koc family, which runs the most valuable company on the Borsa Istanbul, sold 107 million shares for about $475 million in Koc Holding AS, according to a term sheet seen by Bloomberg News. In a separate deal, some members of the Sabanci family sold about $100 million in shares in Sabanci Holding, bookrunner Unlu & Co. told Bloomberg.

The sellers of the Koc shares included the Istanbul-based conglomerate’s honorary chairman Rahmi Mustafa Koc. Citigroup Inc. was the sole bookrunner in the private placement. Other sellers were Chairman Omer Koc, deputy chairman Ali Koc and Caroline Koc, the widow of late chairman Mustafa Koc, who died in January of last year.

The Koc sale was concluded at 15.87 liras a share, at the bottom of the guidance range and about 6.8 percent below Wednesday’s closing price of 17.02 liras. Settlement will be on June 1, according to the term sheet. The shares rose as much as 1.1 percent to trade at all-time high of 17.18 liras on Wednesday.

Koc Holding, which has interests in industries ranging from automobiles to defense, energy and banking, had a market capitalization of $12.1 billion as of Wednesday, the highest on the Turkish exchange.

Members of the Sabanci family, owners of Turkey’s second-largest group of companies, also sold about $100 million in traded shares in Sabanci Holding to 21 international institutional investors, according to Unlu & Co. The shares were sold at about 4 percent below Wednesday’s closing price of 11.10 liras per shares, Unlu said.

The sales come after a 26 percent year-to-date rally in the benchmark Borsa Istanbul 100 index brought it to a record high close of 98,313.77 on Wednesday.

Spokesmen for the two companies didn’t immediately respond on Wednesday to questions about their motivations for the sales.

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