(Reuters) - A former employee at S&P Dow Jones Indices pleaded guilty to insider trading on Thursday, admitting that he tipped a friend before companies were added to or removed from S&P indices last year in a scheme that netted more than $900,000.

Former S&P Dow Jones Indices senior index manager Yinghang Yang, 27, of Flushing, New York, pleaded guilty to one count of securities fraud in a remote hearing before U.S. Magistrate Judge Ramon Reyes Jr. Yang was arrested in September on allegations of sharing nonpublic information so his friend could trade in companies including T-Mobile and Grubhub before the index changes affected their share prices between April and October 2019.

Yang, also known as James Yang, told the court on Thursday that he personally received $105,000 from the scheme. He said his parents, who he lives with, had taught him to be "honest and honorable," and that he is deeply ashamed of his behavior and plans to pay back the money.

The sentencing guidelines Yang agreed to in his plea deal call for 30-37 months, but the ultimate sentence will be determined by U.S. District Judge Frederic Block at a later hearing. Yang's attorney Edward Sapone of Sapone & Petrillo confirmed during the hearing that he intends to ask the judge for no prison time.

April Kabahar, a spokeswoman for S&P Dow Jones Indices, said his employment was terminated the week the charges were announced on Sept. 21. The alleged conduct is "contrary to our company's code of conduct and deeply held ethical values," she said.

In the criminal complaint, Brooklyn federal prosecutors accused Yang of tips that led to put and call options trades in the unnamed friend's account around the same time index changes were announced. The trades included purchases of options to buy T-Mobile and Grubhub stock just ahead of announcements that the companies would be added to the S&P 500 and S&P MidCap 400, respectively.

The U.S. Securities and Exchange Commission has also filed a civil lawsuit accusing Yang and his friend of insider trading. The SEC said the pair only used the information to trade in the friend's account in order to hide the trades from Yang's employer, which prohibited employees from insider trading in its code of ethics.

The case is U.S. v. Yang, U.S. District Court, Eastern District of New York, No. 20-cr-00531.

For Yang: Edward Sapone of Sapone & Petrillo

For the government: Lindsay Gerdes of the U.S. Attorney's Office for the Eastern District of New York