Walmart, the giant retailer, is constantly looking for ways to expand its business. Humana, the health insurer, is watching the consolidation taking place in its industry and looking for a partner.

Now the two companies are exploring ways to strengthen their ties, people briefed on the matter said Friday, the latest sign of the disruptive pressure that is forcing new alliances in the health and retail industries.

Walmart is unlikely to end up taking over Humana, these people said, but the deal could result in a financial and operating partnership around prescription drug sales or insurance coverage.

While much of the focus in retail is geared toward millennials, Walmart’s discussions with Humana involve another large and lucrative market — the health care needs of Americans over 65.