[Photo: Wall Street Analyst Mike Mayo,  by Scott Mlyn / CNBC]

CLSA Ltd, the brokerage owned by China’s Citic Securities, shut down its U.S. equity-research operations Monday, laying off 90 employees - more than half of workers based in this country. Most of those affected work in research, including research sales support staff and several traders.

The terminations include analysts Mike Mayo, an MD who covered banks, and Avi Silver and Ed Maguire, both of whom wrote about technology firms.

Financial research houses are facing revenue pressures, including from a proposal in Europe to make investors pay for investment analysis separately from trading commissions. While CLSA CEO Jonathan Slone said the move wasn’t directly linked to the so-called MiFID initiative, he said last week that investors should be allowed to decide what they want to pay for analyst research without too many regulatory restrictions.

While the rules - under the Markets in Financial Instruments Directive (MiFID)- are a European initiative, banks in Asia are also feeling the effects. Global investors have been allocating a smaller proportion of their commission payments to brokers that provide equity research and advisory services in Asia over the past 2 years, according to a survey released last month by Greenwich Associates.

Citic Securities, which bought CLSA from French bank Credit Agricole in 2013 for about $1.2 billion, considered selling the HK-based brokerage last year

The firm’s Americas unit will now employ 85 workers to execute U.S. and Asia stock trades, plus Asia equities sales