The Apache Corporation agreed to sell its business in the Gulf of Mexico's shelf to a portfolio company owned by the private equity firm Riverstone Holdings for about $3.75 billion.
The buyer, Riverstone's Fieldwood Energy, is buying a business with 239 millions of barrels of oil equivalent in reserves at the end of last year, more than half of which is oil and 75 percent of which is already developed.
The deal is the biggest sale on record by Apache, which has spent $15 billion in acquisitions over the last three years alone, according to Standard & Poor's Capital IQ. In a statement, the company said that the deal is meant to help rebalance its portfolio, though it will also offload about $1.5 billion worth of asset retirement obligations.
Apache will retain a 50 percent stake in all exploration blocks in the assets, and it will work with the buyer, Fieldwood Energy, in developing deep-water sites in the holdings.
“At the end of this process, we expect Apache to have the right mix of assets to generate strong returns, drive more predictable production growth, and create shareholder value,†G. Steven Farris, Apache's chairman and chief executive, said in a statement.
The deal is one of the biggest takeovers associated with Riverstone alone, according to Capital IQ, although the firm has partnered with others on some of the biggest energy-related private equity firms in history.
“We have had a long-standing and strong relationship with Apache's executive management and have been great admirers of their entire organization and their Gulf of Mexico operations for many years,†Pierre F. Lapeyre Jr. and David M. Leuschen, Riverstone's co-founders, said in a statement.
Apache was advised by Goldman Sachs and the law firm Bracewell & Giuliani.
Fieldwood is receiving financing from Citigroup, JPMorgan Chase, Deutsche Bank, Bank of America Merrill Lynch and Goldman. It received legal counsel from Vinson & Elkins a nd Simpson Thacher & Bartlett.
A version of this article appeared in print on 07/19/2013, on page B7 of the NewYork edition with the headline: Apache's Sale.