The trustees of the $16.9 billion public workers pension fund have fired their chief investment officer, instructing him on Monday to leave the offices of the Employees’ Retirement System and not return, according to sources familiar with the action.

Vijoy “Paul” Chattergy joined the ERS as an investment specialist in 2011, and became its fourth chief investment officer late the following year. His salary was $240,000 annually.

Officials familiar with the situation said some of the eight ERS trustees cited problems with Chattergy’s “management style” as the grounds for his termination.

Chattergy did not respond to requests for comment Wednesday, and ERS Executive Director Thomas Williams refused to discuss the matter.

“I’m not at liberty to discuss confidential personnel matters,” Williams said. He added that “things are going exceedingly well here at the ERS.”

The public pension fund provides retirement, disability and survivor benefits to more than 122,079 active and retired state and county employees.

The ERS had an unfunded liability of more than $12.9 billion as of June 30, 2017, but the state has taken steps to accelerate its contributions into the system. The fund’s investments posted a 16.1 percent gain in calendar year 2017, and its performance in the first half of the 2018 fiscal year has been running ahead of its targeted rate of return of 7 percent, according to ERS officials.

Chattergy is a graduate of Punahou School, and has a master’s degree from the London School of Economics as well as an MBA from Cornell University.

Chattergy was one of five employees at the ERS who are exempt from ordinary civil service protections, and serve at the pleasure of the board of trustees. The performance of those employees is regularly reviewed by the trustees’ compensation committee, which makes recommendations to the full board.

His termination came as a surprise to several people familiar with the ERS, but those observers did not want to be identified.

“There’s things you hear about, but I never really talked to anybody about it, and never really thought that it would come down to what you’re telling me,” one person said. “I was kind of surprised, anyway.”

Chattergy has been honored with a number of awards, and was the recipient of a 2017 Industry Innovation Award from Chief Investment Officer, an organization designed to connect and inform asset owners and advisers. His personal profile published at the time of the award credited him with overhauling the pension fund’s investment portfolio.

Chattergy told Chief Investment Officer that he has friends and family members who are both retired and working employees within the system.

“Even if I’m not sitting here in this seat, I know that for decades to come, my family will benefit from this pension plan,” Chattergy told the publication. “It really is a unique job for me because the alignment is so strong with two generations of my family devoting nearly 100 years of service to the state of Hawaii.”