Credit Suisse analyst Ashley Serrao thinks macro conditionspoint to an M&A lull that will favor investment bankers with a strong anddiverse backlog of advisory fees. Greenhill & Co.Inc.'s backlog is concentrated around one acquisition, and based onhis economic forecast, the analyst downgraded the company to"underperform" from "neutral."

Serrao noted that 31% of Greenhill's enhanced backlog isrelated to their service in Teva Pharmaceutical Industries Ltd.'s deal toacquire Allergan Generics, leaving about $50 million in revenues for Greenhillto replace during what the analyst thinks will be a quiet second half in dealsfor 2016.

The bank's advisory announcements this year have lagged itspeers, amplifying the backlog risk and pressuring 2017 revenues, Serrao wrote.Greenhill has cash warehoused overseas for tax reasons and has increased itscredit facility to meet substantial payment obligations in the U.S. thatincludes paying down debt from the acquisition of Cogent Partners LP and funding dividendand bonus payments.

"But this all comes at the cost of share countcreep," Serrao said, adding that he incorporated that dilution into hisestimates.

Serrao's target price for Greenhill is $13. He lowered hissecond-quarter EPS estimate to 37 cents from 70 cents. He held his 2016 fiscalyear EPS estimate at $1.33 but lowered his 2017 estimate to $1.07 from $1.15.For 2018, Serrao raised his estimate to $1.24 per share from $1.02 per share.