The San Francisco company says its stockholders will receive $21 in cash for each share from Thoma Bravo and the Ontario Teachers' Pension Plan. That represents a 12 per cent premium to the stock's Friday closing price.
Riverbed Technology Inc. said in October that its board would review ways to enhance shareholder value, and it planned to cut costs by up to $25 million.
Riverbed shareholders and government regulators still need to approve the deal, which is expected to close in the first half of next year.
Its shares climbed 9 per cent in morning trading Monday.