(Recasts with Sabanci)
By Ezgi Erkoyun
ISTANBUL, May 25 (Reuters) - The founding families of Turkey's two largest conglomerates, Koc Holding and Sabanci Holding, have agreed to sell a combined $580 million in shares of their firms, capitalising on a global stock market rally that has pushed Istanbul shares to record highs.
Koc and Sabanci, conglomerates that span banking to white goods to retail, have long been synonymous with corporate Turkey and its secular, Western-facing elite. Members of the Koc family will sell a 4.22 percent stake in their firm, worth nearly $480 million, according to a statement filed to the Istanbul stock exchange on Thursday.
Members of the Sabanci family have agreed to sell approximately $100 million worth of shares in their firm at a 4 percent discount to Wednesday's close, according to brokerage Unlu & Co which is authorised for the transaction.
The sales comes as Turkish equity prices have powered to record highs, buoyed by strong performances in overseas markets. Turkey's BIST index rallied over 25 percent from the beginning of 2017 and touched a record high on Wednesday.
The Koc family, which will retain a more than 11 percent stake in their company, will sell their shares at 15.87 lira each. That represents a 6.8 percent discount from Wednesday's closing price of 17.02 lira and values the stake at 1.7 billion lira ($478.23 million).
Shares of Koc, which as of Wednesday's close had risen 25 percent since the start of this year, dropped 6.5 percent to 15.9 lira while shares of Sabanci Holding dropped 3.4 percent.
Earlier this month, Koc said its first-quarter net profit more than doubled to 1.1 billion lira ($304 million) while total revenues surged 59 percent to 22.274 billion lira. ($1 = 3.5548 liras) (Editing by Daren Butler and David Dolan)