KKR’s offer of $46 per share represents a premium of 5.4% to Envision’s last close on June 8. Including debt, the deal is valued at approximately $9.9 billion. This is one of the largest private equity buyouts since the financial crisis.

“Today’s announcement reflects the extensive efforts by our team to explore all opportunities to deliver value for our shareholders,” said Envision president and CEO Christopher A. Holden.

KKR already owns Envision’s AMR, which is the biggest U.S. provider of ambulance service. The firm scooped it for $2.4 billion last year and merged it with its helicopter ambulance service. KKR also took WebMD Health private for about $2.8 billion in 2017.

The acquisition agreement comes on the heels of KKR’s announcement that it will buy U.S. business software company BMC Software in a deal that values the company at about $8.5 billion, including debt.

The deals are part of a larger trend in private equity. Dry powder—money raised but not yet invested—is at record levels in the PE industry. At the end of 2017, buyout funds were sitting on an all-time high of $633 billion.

Hugh McArthur, the head of Bain’s global private equity practice, told Fortune in February that the average size of PE deals keeps increasing while the amount of deals getting done is down.

“So the trouble is that we’ve got a mountain of dry powder, but we’ve got a flat number of deals and an increasing value per deal, so you quickly come to a situation where the industry is becoming much more competitive for each deal that is done,” he said. “As a result, the prices are at an all-time high.”