"Peter has jokingly described us as 'friendly competitors', but I think our shared focus on people and a commitment to do the best for our clients makes this development more of a win-win than any sort of truce," he said.
The company would operate throughout the South Island and into the North Island, providing insurance, agri-supplies, funding and procurement services, as well as livestock broking.
Peter Walsh & Associates was established in 2002 by Walsh and Hamish Lane.
It now has more than 30 livestock brokers, a regional manager and two sales co-ordinators.
Hazlett was launched in 2008 as a livestock broking service and, since then, has extended to provide insurance, agri-supplies and funding solutions to businesses of many types.
Peter and Karen Walsh would continue to be involved in the business, the statement said.