The Securities and Exchange Commission charged Barclays PLC for the sale of $17.7 billion in unregistered securities, the regulator said Thursday. “This case highlights why it is essential for firms like Barclays BCS, -2.70% to have robust internal controls over their offers and sales of securities,” said Gurbir S. Grewal, director of the SEC’s Division of Enforcement, in a statement. “The control deficiencies and the scope of the conduct at issue here was simply staggering.” The bank agreed to pay a $200 million civil penalty and a disgorgement and prejudgment interest of more than $161 million in connection with the case. Barclays self reported its over-issuance to regulators and provided “meaningful cooperation” during the SEC’s investigation, the SEC said.