The deal, BP's largest since acquiring oil company Atlantic Richfield Co in 1999, will increase its US onshore oil and gas resources by 57 percent.
BP will take over the unit from BHP, which holds the assets of Eagle Ford, Haynesville and Perm at $ 10.5 billion, giving it "some of the best land in some of the best catches in the onshore US" ,
It struck competitors such as Royal Dutch Shell and Chevron Corp. for assets that combined a production of 190,000 barrels of oil equivalent per day (boe / d) and 4.6 billion barrels of oil equivalent resources.
BP said the transaction would increase its earnings and cash flow per share and continue to be able to maintain its leverage within a range of 20 to 30 percent.
The company also said it would increase its quarterly dividend by 2.5 percent to 1
In the meantime, a unit of the Merit Energy Company will buy BHP Billiton Petroleum (Arkansas) Inc and the assets of Fayetteville for $ 0.3 billion.
Evanes of Tribeca welcomed the clean exit for cash rather than asset swaps, which BHP had identified as a possibility.
"The company has plenty of room to concentrate on its much better offshore oil business," he said.
BHP CEO Andrew Mackenzie said the company had kept its promise of value for its shale assets, while the sale was consistent with a long-term plan to simplify and strengthen its portfolio.
BHP shares rose 2.3 percent after the announcement, outperforming the broader market and rival Rio Tinto.
BP said it would pay the $ 10.5 billion in installments over a six-month period from the date of completion, with $ 5.25 billion of the consideration to be raised by selling new shares.
Elliott had no immediate comment on the sales announcement.