Houston-based land driller Sidewinder Drilling Inc. management on Monday said it now holds about 92% of the outstanding shares of Union Drilling Inc., which allows the unconventional oilfield service operators to move forward with their merger, first announced in September.

The all-cash tender offer, which in late September was valued at about $242 million, was on track to close Monday (see Shale Daily, Sept. 26).

Sidewinder, which is a portfolio company of private equity company Avista Capital Partners, owns and operates a fleet of land rigs that target unconventional oil and natural gas resource plays in the United States. Union, which is headquartered in Fort Worth, TX, also specializes in unconventional drilling techniques, providing contract land drilling services and equipment to U.S. producers. Union now owns 53 rigs, including two that are under construction.

Sidewinder’s Fastball Acquisition Inc. was moving forward with the “short-form” merger, as allowed under Delaware’s laws, where it is incorporated.

Union is to survive as a Sidewinder subsidiary. Nasdaq-traded stock held by Union shareholders is to be canceled and converted into the right to receive $6.50/share in cash from Sidewinder.