Private equity firms Vista Equity Partners and Blackstone are buying software maker Smartsheet for approximately $8.4 billion in cash.

Vista and Blackstone said Tuesday that they will pay $56.50 per Smartsheet Inc. share. The agreement includes a 45-day "go-shop" period during which Smartsheet and its advisers seek alternative acquisition proposals from certain third parties and possibly enter into talks with other parties that make alternative offers. Smartsheet's board will have the right to end the deal with Vista and Blackstone to accept a superior proposal. The go-shop period expires on Nov. 8.

"We look forward to partnering closely with Blackstone and Smartsheet to support its ambitious goal of making its platform accessible for every organization, team and worker relying on collaborative work to achieve successful outcomes," Monti Saroya, co-head of Vista's Flagship Fund and senior managing director, and John Stalder, managing director at Vista, said in a statement.

The announcement comes shortly after the Federal Reserve said that it cut its benchmark interest rate by an unusually large half-point. The central bank's action lowered its key rate to roughly 4.8%, down from a two-decade high of 5.3%. A rate cut gives more favorable conditions for businesses looking at making acquisitions.

The deal, which was approved by Smartsheet's board, is expected to close in the company's fiscal fourth quarter. It still needs approval from Smartsheet's shareholders.

Once the transaction closes, Smartsheet will become privately held. The Bellevue, Washington company will continue to run under the Smartsheet name and brand.

Shares surged more than 6% in morning trading.