The prolonged slump in oil and gas prices has dampened deal activity in the sector, with value of transactions down 19% during the first quarter over the year-earlier period, according to PricewaterhouseCoopers LLP.

For the first three months of 2016, 39 oil and gas deals totalling $28 billion were announced, down 19% from $34.4 billion across 39 deals a year earlier, said the accounting and consulting firm. Factors that hampered deal activity include constrained cash flow and overlevered balance sheets, PwC said.