Sept 9 (Reuters) - Box Inc (BOX.N)won a proxy contest against Starboard Value after the cloud services provider"s shareholders backed all three board directors the hedge fund was challenging, Box said on Thursday. Shareholders re-elected Aaron Levie, Box"s co-founder and chief executive officer, as well as directors Peter Leav and Dana Evan to the company"s 10-member board in one of the season"s most bitter boardroom battles. The vote was a blow to Starboard, which criticized Box anew this year after having settled with the company last year. Starboard, which owns an 8.4% stake in Box, has not lost a proxy vote in nearly a decade since falling to AOL in 2012. It is known in the industry for having won big victories at Darden Restaurants in 2014 and at GCP Applied Technologies last year and traditionally wins more board seats than any other activist investor, according to bankers and analysts. Box promised after the vote to "remain focused on continuing to transform Box." Starboard said in a letter to shareholders that the results were skewed "by the voting rights tied to preferred equity financing and the use of stockholder capital to aggressively repurchase shares ahead of the record date from stockholders likely to support change." The vote tally remains preliminary but according to two sources the hedge fund received less than 15% of the outstanding shares, excluding their own. Since Starboard"s involvement with Box became public last year, Box"s stock price has climbed 71%. The stock climbed 20% since Starboard announced in May that it was nominating candidates to the board. On Thursday, it traded at $24.50, off 3.3% in late-morning trading. Starboard"s criticisms of Box this year centered around the company"s decision to raise capital, as well as its track record of being a publicly traded company and its ability to deliver on commitments. Starboard was especially concerned with a $500 million convertible preferred offering led by private equity giant KKR, which the hedge fund described as a defensive tactic. Starboard nominated three directors, including Peter Feld, one of the hedge fund"s partners and its director of research. Starboard launched this year"s fight after having reached a settlement with Box in March 2020 that allowed it to choose one director and have input in choosing a second. Both of those directors have assumed leadership roles on the board.Proxy advisory firm Institutional Shareholder Services recommended that investors elect company directors, arguing that even though Starboard deserves credit for operational and governance changes made since last year"s settlement, the current board deserves more time for changes to bear fruit. Glass Lewis, a rival proxy adviser, recommended that shareholders elect Feld to the board, arguing that it would make sense to add a direct shareholder representative to the board. "We will continue to monitor progress at Box, and we hope to see the Company embrace the changes catalyzed by our involvement and create long-term value," Feld wrote to shareholders on Thursday.