Nabors Industries Ltd. has gotten so cheap that traders in the options market are betting the world's largest land-drilling contractor may be a takeover candidate after the departure of its 81-year-old chief executive officer.

Nabors, which lost $2.4 billion in value in the past six months as delays in equipment deliveries and upgrades of rigs in Saudi Arabia cut profitability, is now cheaper than 97 percent of oil and gas services companies versus sales, according to data compiled by Bloomberg. In the past two weeks, calls priced 10 percent above Nabors' stock rose the most in 18 months versus puts on one-month contracts, signaling traders are anticipating an acquisition, said JonesTrading Institutional Services LLC.

Gene Isenberg, who led Nabors since 1987 when it emerged from bankruptcy, was replaced in October as the board appointed his deputy the company's CEO. While Isenberg remains chairman, the change in leadership may have opened the door for a takeover of Nabors that could be worth 39 percent more than its market value of $5.2 billion, according to Penn Capital Management. A potential suitor such as Baker Hughes Inc. or Schlumberger Ltd. would gain more than 1,200 rigs from the Americas to Africa and the Middle East, Greenwood Capital said.