By Reuters Staff 2 Min Read (Reuters) - Pluralsight Inc said Vista Equity Partners had increased its all-cash offer to buy the U.S. learning software company after investor groups said the initial bid was not sufficient and complained about how Pluralsight had run its sale process. Shares of Pluralsight rose 7.4% to $22.08 on Monday after the private equity firm raised its bid to $22.50 per share from $20.26 per share The enterprise value for the amended deal is about $3.8 billion, a Pluralsight spokesperson said. On Dec. 13, Vista Equity first agreed to acquire Pluralsight in a deal valuing the learning software company at $3.5 billion.