Former Merrill Lynch stockbroker Gary Yin pleaded guilty to one felony count covering the laundering of money and obstructing justice in an insider stock trading case involving one of his clients, a former top Qualcomm executive, federal prosecutors said.

Yin’s plea agreement follows the arrest of his client Jing Wang, a former Qualcomm executive vice president and president of global business operations, on multiple charges of insider stock trading and obstructing an investigation Sept. 23.

Wang, 51, of Del Mar, pleaded not guilty to the charges and was expected to be released on a $3 million bond Sept. 24.

In his plea agreement, Yin says he helped Wang conduct the stock trades using a secret brokerage account that he set up for a shell company based in the British Virgin Islands.

Yin also says he assisted Wang by delivering documents to Wang’s brother, Bing Wang, a Chinese citizen who was also charged in the case.

Yin also claims he conspired with Jing Wang to conceal the true ownership of the brokerage account when questioned by federal agents, and in moving about $525,000 to another shell account to avoid detection from federal regulators, according to the plea agreement.

Jing Wang is accused of using information he had of Qualcomm corporate plans to purchase and sell its stock as well as stock of a company Qualcomm acquired. According to an indictment of Wang, he illegally gained about $250,000 from the transactions.

A spokeswoman for Qualcomm, San Diego’s largest public company, said that Wang joined Qualcomm in 2001, and resigned in early May of this year. He had been on leave since May of 2012.

“Qualcomm has been aware of the investigation and has been cooperating fully with the government’s investigation,” said Christine Trimble, vice president of public affairs. “This is an individual matter involving Mr. Wang, who is no longer employed by Qualcomm, and this matter will now be addressed through the legal system.”

— Mike Allen