"As you look at expansion of the unconventionals in the U.S., the growth in the deep water in other parts of world, the national oil companies demanding more from the service companies, I just thought a bigger, stronger integrated company was what was needed to compete in this marketplace," he told NBC's "Squawk on the Street."
Baker Hughes brings complementary product lines in areas where Halliburton did not have a large presence, including production chemicals and artificial lift, Lesar said.
Halliburton agreed to buy Baker Hughes in a cash and stock deal worth $34.6 billion on Monday.
Responding to an analysis in The Wall Street Journal that the deal's value for shareholders will have to come from a higher multiple down the line, Lesar said he believes the company's multiple will indeed increase.
He added that Halliburton expects the deal to be accretive on a cash flow basis one year after the deal closes, and the company plans to buy back shares with proceeds from interests it expects to divest in order to win approval from anti-trust regulators.
"I can tell you we're laser focused on returns to shareholders. We are laser focused on getting that money back to them," he said. "You will see money coming back, and you'll continue to see buybacks."
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Lesar said the energy industry can weather the current low oil price market so long as prices settle for a while.
"I've always said the fairway for the oil and gas operators, especially the unconventional players in the U.S., is between $80 and $100," he said "What really hurts the industry is volatility. Our industry is a great, adaptable industry. If prices will go somewhere and sit for a while, our customers, the service companies, and everybody will be able to adapt and make money at that level."
Halliburton's customers are reviewing their drilling budgets now, but even if oil fell to $65 a barrel, it would only have a marginal impact, he said.