May 9 (Reuters) - Norfolk Southern investors elected three new directors to the railway's board and re-elected the company's chief executive in a bitter boardroom battle with activist investor Ancora Holdings, executives said on Thursday.

The preliminary results were announced on Thursday after Ancora waged a proxy fight and pushed to get seven newcomers elected to the 13-member board. Ancora also urged investors to oust CEO Alan Shaw but he was re-elected.

Reuters reported earlier that Ancora was poised to win some board seats.

The fight was one of the year's most closely watched votes because Ancora was pushing for so many seats at such a sizable company, industry analysts and bankers said.

Ancora nominees William Clyburn, Sameh Fahmy and Gilbert Lamphere won seats, according to preliminary voting results, while investors did not support board chair Amy Miles, Jennifer Scanlon, chair of the governance and nominating committee, and John Thompson, chair of the human capital management and compensation committee.

The hedge fund argued new blood was needed to improve financial and operational metrics while Norfolk Southern countered that its team had the right strategy and people in place.

Three prominent proxy advisory firms last week recommended that investors elect at least five of Ancora's seven candidates, arguing that change is needed at the railway which is valued at $52 billion.

Norfolk Southern had argued that replacing its board members with Ancora's candidates would "introduce significant risk, and ultimately destroy long-term shareholder value."

(Reporting by Svea Herbst-Bayliss; Editing by Chizu Nomiyama)