Briefly

Woodland Hills-based Zenith National Insurance Corp. said Monday that it had received letters of inquiry from the California Department of Insurance requesting information about its arrangements and dealings with its agents and brokers.

The state agency is among several regulators conducting wide-ranging probes into industry practices. Zenith said it was cooperating with the request, which it announced after the stock market closed. Zenith shares declined 4 cents to $49.79 on the New York Stock Exchange.