Call it the age of the mega merger. Across industries, some of the biggest companies are joining hands and creating even bigger companies.

While this is not a new concept, the increased costs of technology, dwindling revenues and high valuations may be driving even more mega mergers than in previous years. 2019 saw 38 megadeals globally, or deals valued at more than $10 billion. That was the highest number of megadeals since 2015, according to the research firm Mergermarket. United Technologies Corp.’s purchase of Raytheon Co. was the year’s largest  at $88.9 billion, the firm said.

Hospital systems are driving megamergers in the healthcare industry. According to a Modern Healthcare report, mega mergers pushed deals to new heights. One example is the 2019 agreement between Charlotte-based Atrium Health and Winston-Salem-based Wake Forest Baptist Health, both in North Carolina, that created a combined 49-hospital system, an additional 1,300 care locations and $13 billion in annual revenues.

The average revenue of an announced seller jumped from $196 million in the first quarter of 2019 to about $597 million in the second quarter of 2019, according to a report from consulting firm Kaufman Hall & Associates. Health systems now want to serve entire regions or multiple counties, a shift from their pre-2010 mentality, when many were content to serve just one city, according to Anu Singh, a managing director at Kaufman Hall. Hospitals face increasing costs, with flat or declining inpatient volumes, downward pressure on commercial insurance rates and an increasing percentage of Medicare and Medicaid patients, the firm has said.

Telecommunications firms are also combining to become more competitive, as seen in the $26.5 billion pending merger of Sprint Corp. and T-Mobile US, which has been held up in a multistate lawsuit.

In banking, SunTrust Banks and BB&T Corp. recently merged to become Truist Financial in a $66 billion combination in the largest banking deal since the financial crisis. The new company is now the sixth largest bank in the United States and better able to compete in an increasingly digital finance industry.

“We face a fundamental choice — disrupt our business or be disrupted,” BB&T Chairman and CEO Kelly King said in his annual shareholder letter.

Of course, not all mega mergers actually close. In fact, these deals suffer a high rate of failure, as they are more difficult to get done, notes Bloomberg Law. The Fiat Chrysler Automobiles tie up with Renault, which would have created the third largest automaker in the world, fell apart in 2019 amid the complications of combining the two companies. (The French government partially owns Renault and had requested more time to review the deal.)

So far, the U.S. government has been approving big company acquisitions. That could change. Democratic presidential hopeful Elizabeth Warren is drafting regulation to ban mega mergers, defined as deals where combined revenues top $40 billion, and to increase antitrust scrutiny.