Dec 20 (Reuters) - Elliott Management Corp, the hedge fund that has amassed a stake in Citrix Systems Inc (CTXS.O), has partnered with Vista Equity Partners for a joint bid for the U.S. cloud computing company, people familiar with the matter said. Bloomberg News first reported the bid on Monday. A bid for Citrix, which has a market value of more than $10 billion, would come after its shares dropped to their lowest level since 2018. The company"s products allow employees of companies to access their network remotely. However, it failed to capitalize on the rise of virtual working during the COVID-19 pandemic because it spent too much on its salesforce and too little on its distribution partners, Citrix interim chief executive Robert Calderoni told analysts on the company"s latest quarterly earnings call last month. Elliott"s private equity arm is working with Vista on a bid for Citrix, the sources said. The deal could involve one of Vista"s portfolio companies, Tibco, which provides data analytics software. The price that is being discussed could not be learned. The sources cautioned that the talks are in an early stage and no deal is certain. They requested anonymity because the matter is confidential. Citrix and Vista did not immediately respond to request for comment. Elliott declined to comment. While Citrix has struggled to transition to a subscription-based business, demand for its cloud services soared during the pandemic as companies shifted to remote working models. Still, the company reported operating income of $84.5 million in the third quarter, down from $128.3 million a year ago, as higher operational expenses weighed. Calderoni said he expected to announce a margin improvement program in the fourth quarter. Calderoni took over on an interim basis from David Henshall, who stepped down last month, having served as Citrix CEO since 2017. Elliott managing partner Jesse Cohn joined the Citrix board of directors in 2015 and stepped down last year. Reporting by Krystal Hu and Greg Roumeliotis in New York Additional reporting by Mike Spector in New York; Editing by Sam Holmes