By Chris Prentice and Kanishka Singh

NEW YORK/WASHINGTON (Reuters) -A Goldman Sachs & Co unit has agreed to pay $15 million to settle U.S. Commodity Futures Trading Commission (CFTC) charges that it failed to make proper disclosures and communicate fairly to swap customers, the regulator saidon Monday.

In 2015 and 2016, Goldman opportunistically sold clients on so-called “same-day” swaps at times that financially benefited the bank and hurt the customers, the CFTC said in a settled order. As part of the settlement, the bank admitted it failed to disclose key information for nearly all “same-day” swaps executed in 2015 and 2016, according to the regulator.

Goldman “saw an opportunity” in buying or selling swaps when they were trading at a premium or discount to the projected settlement prices of certain equity indexes, the CFTC said. The firm did not disclose key marks to customers for assessing the swap’s value and did not communicate to them in a fair and balanced manner, the regulator said.

By depriving clients of transparency into the relative value of the swaps it was offering, Goldman violated CFTC’s business conduct standards for swap dealers, the regulator said.

The “CFTC will aggressively pursue swap dealers that violate these business conduct standards” that promote fairness in the swaps market, enforcement director Ian McGinley said in a statement.

A spokesperson for Goldman declined to comment.

(Reporting by Chris Prentice in New York and Kanishka Singh in Washington; Editing by Chris Reese and Aurora Ellis)