HOUSTON-Oasis Petroleum has signed a seven-year lease for 26,816 square feet in First City Tower. The local company, which focuses on the acquisition and development of unconventional oil and natural gas resources, is expanding by 13,290 square feet and relocating its headquarters from the second floor to the 15^th floor of the 49-story building.

Oasis Petroleum has been a tenant in the 1.3-million-square-foot tower since 2007, according to Michael Anderson with Colvill Office Properties. He and Chip Colvill represented the building owner, FC Tower Property Partners LP, an affiliate of JMB Realty of Chicago, in lease negotiations. Chad Beck of Jones Lang LaSalle’s local office represented Oasis Petroleum.

Anderson tells GlobeSt. that Oasis Petroleum recently had an initial public offering and needs additional space to accommodate its future growth. Although the company did consider other downtown buildings, the building owner was able to terminate Oasis Petroleum’s lease early – it had about 18 months left on its initial term – and offer a new lease.