Complex sentence: The market for corporate control is a description of the role of equity markets in facilitating corporate takeovers first put forward in an article by HG Manne, "Mergers and the Market for Corporate Control".
Split into simpler sentences: The market for corporate control is the role of equity markets in facilitating corporate takeovers. This was first described in an article by HG Manne, "Mergers and the Market for Corporate Control".