Dec 16 (Reuters) - Earthstone Energy Inc (ESTE.N) said on Thursday it would buy the assets of Warburg Pincus-backed Chisholm Energy Holdings LLC located in the northern Delaware Basin of New Mexico in a $604 million cash-and-stock deal, as the oil and gas producer beefs up its presence in the Permian. The deal comes months after Earthstone said it would buy privately held assets from two sellers for about $73.2 million in cash and stock. "When this acquisition is combined with the previous four acquisitions completed in 2021, we will have increased our Permian Basin net acreage footprint by approximately 400%," Earthstone Chief Executive Officer Robert Anderson said in a statement, adding the acquisitions will nearly triple the company"s daily production rate and boost free cash flow generation capacity. The energy sector has seen a boom in dealmaking as crude prices have recovered from pandemic lows, encouraging producers to pursue deals as they seek to ramp up production. Reuters in September reported that Warburg Pincus and the Ontario Teachers" Pension Plan were exploring a sale of Chisholm Energy, citing people familiar with the matter. The effective date of the Chisholm deal will be Nov. 1, with the transaction expected to close in the first quarter of 2022, Earthstone added.