Paul Singer’s activist hedge fund Elliott Management has taken stakes in two telecom equipment makers and laid out an aggressive plan to consolidate their industry. The fund disclosed stakes of approximately $100 million in Polycom and Mitel, equating to stakes of 6.6% and 6.3%, respectively, in the companies. The stakes put Elliott among the biggest shareholders of both firms, according to regulatory filings. In conjunction with the disclosures, Elliott also sent a letter to Polycom’s board of directors in which it noted the company’s underperformance and urged a full strategic review of all options. The letter, written by Elliott senior...