MUMBAI — Walmart’s joint venture in India has suspended several senior executives and delayed the opening of some stores in the country as part of an internal bribery investigation, the company said Friday.

It is the latest in a series of setbacks for the retail giant’s international operations, and comes at a particularly sensitive time here, after Indian policy ­makers this fall started allowing foreign retailers like Walmart to open stores in the country. The investigation seems to have emboldened opposition lawmakers trying to overturn the government’s decision.