Citigroup Global Markets has been fined a total of $11.5m by the Financial Industry Regulatory Authority (FINRA) for displaying inaccurate research ratings for equity securities.

Under the settlement agreement, the firm has to pay $5.5m to FINRA and at ‎least $6m in compensation to affected customers.

FINRA said that the firm offered inaccurate research ratings for over 1,800 equity securities to its brokers, retail clients and supervisors owing to problems in electronic feed of ratings data. The inaccuracies occurred between February 2011 and December 2015.

The firm was accused of displaying wrong ratings for some covered securities or ‎displaying ratings for other securities that the firm did not cover.‎

The regulator alleged that the errors led to the firm’s CGMI brokers soliciting thousands of transactions inconsistent with the firm’s actual ratings, as well as soliciting transactions that breached the firm’s guidelines.

At the same time, the watchdog also accused the firm of failing to effectively address the issue despite several red flags alerting it of the same, and carry out trial to verify the accuracy of research ratings data.

The firm agreed to the fine, without admitting or denying the allegations. In determining the fine, FINRA considered the firm’s cooperation in the matter.

FINRA executive vice president and head of enforcement Susan Schroeder said: “Member firms must reasonably ensure that the research rating information that they display and on which they rely to supervise business activities is complete and correct. The display and use of incomplete and inaccurate research ratings can have widespread, adverse consequences to customers. Even when such inaccuracies are caused by technology problems, firms should react quickly to address those errors.”