The news agency reports that Dyal has been with the company for 16 years, according to the memo.
The memo, signed by CEO Lloyd Blankfein and Chief Operating Officer Gary Cohn, highlighted Dyal's role in leading merger transactions and building relationships with clients globally.
In the meantime, Reuters also reports that Standard Chartered remains committed to Islamic banking and expects growth in its core markets, a spokesman for the bank said on Sunday, after the head of its Islamic arm departed.
Afaq Khan left Standard Chartered Saadiq, the bank's global Islamic banking business, after 12 years with the Asia-focused bank to take a career break, the spokesman said. A successor will be announced in due course, he added.