Mr Groves said economic times were largely to blame.
"Unfortunately, we have succumbed to the economic times and have decided to close our doors," Mr Groves said.
"Wanganui Taxis will still be out there until August 26 when all vehicles will change to River City Cabs. Our friendly drivers will still be out there continuing to service the transport requirements of the Wanganui public after that date.
"We would like to reassure the public of Wanganui that at all times the Wanganui Co-operative Taxi Society has always worked with Land Transport New Zealand and have always adhered to legislative requirement.
"We consider the joining of the two companies to be beneficial to the local taxi industry," Mr Groves said.
The company has serviced Wanganui transport needs for more than 50 years and in recent times had 11 owner/drivers within the 17-strong fleet.