Rig services company Schlumberger said the acquisition of a Houston-based systems company is part of a long-term strategy to build depth of service.

Omron Oilfield and Marine Inc., a subsidiary of Japanese company Omron Corp., moves under the Schlumberger umbrella as part of a merger for which terms were not disclosed. The Japanese parent, which employs about 38,000 people worldwide, said the impact of the sale on its earnings for the fiscal year ending March 2017 would be negligible.

Omron Oilfield and Marine employs 139 people at a Houston office who design and manufacture oil-drilling and control systems. Ashok Belani, a vice president for technology at Schlumberger, said the acquisition offers a broader portfolio of options to its customers.

"The addition of Omron Oilfield and Marine will enable us to strengthen our industrial automation control systems capabilities as part of our long-term strategy to develop an integrated well construction system," he said in a statement.

Schlumberger, the world's largest oil field services company, has been in the process of acquiring niche players in the industry during the market downturn. Last month, it entered into an agreement to acquire drilling services units controlled by Canadian company Xtreme Drilling and Coil Services Corp., which owns a fleet of 11 units in Saudi Arabia and the United States. In early April, it closed on its merger with its smaller industry counterpart Cameron International Corp.

Schlumberger already outlined details of three separate mergers during the first quarter. A merger between its two main industry rivals, Baker Hughes and Halliburton, collapsed this year following U.S. and European concerns about competition.