(Reuters) - Proxy adviser Glass Lewis recommended Norfolk Southern ( NSC ) shareholders vote for six of Ancora Holdings' nominees for board seats at the railroad company, including proposed CEO Jim Barber, in a big win for the activist investor.

In a report dated April 28, Glass Lewis backed six out of Ancora's seven nominees and said Ancora had presented a compelling case for a management overhaul at Norfolk, adding the company has been "consistently worse than its peers for an extended period".

Glass Lewis' backing comes days ahead of Norfolk's May 9 annual general meeting, where shareholders will vote on proposals including board composition and management pay.

Ancora, which has said it owns a large equity stake in Norfolk, on Monday noted Glass Lewis' recommendation and analysis. Norfolk did not immediately respond to a request for comment.

The investor is seeking to replace Norfolk CEO Alan Shaw with Barber, a former United Parcel Service executive.

Glass Lewis said Barber had "compelling credentials" and recommended shareholders withhold support from Shaw.

Norfolk has rejected all of Ancora's nominees saying they would not bring fresh skills or experience, but proposed plans in February to add two new directors to its board to fend off mounting pressure from Ancora.

A group of investors led by Ancora started pushing for major changes at Norfolk earlier this year.

U.S. steelmaker Cleveland-Cliffs, a Norfolk Southern ( NSC ) customer, is also backing Ancora, Bloomberg News reported on Sunday.