(Bloomberg) — Takata Corp. is bracing for further defections after Honda Motor Co., its top customer, began turning its back on the distressed Japanese air-bag maker.

Mazda Motor Corp. said on Thursday its new cars will no longer use Takata air-bag inflators linked to scores of injuries and seven deaths in the U.S., while Subaru-maker Fuji Heavy Industries Ltd. and Mitsubishi Motors Corp. are considering the same. The comments follow Honda's decision to stop using Takata inflators in new models and its accusation that the company manipulated test data, triggering a record two-day, 35%, rout for Takata's shares.

The emerging rifts mark an unusual repudiation in Japan, where corporate relationships are measured in decades and Takata had counted on automakers' support despite more than a year of criticism from U.S. lawmakers and its auto-safety regulator. Even investors appeared to think the worst was over, with the stock up 14% this year through May. The tide turned this week when Honda surprised the market and set the stage for a potential exodus of more customers.