The Washington Post has appointed reporters Fred Hiatt and Patricia E. Bauer as the respective chiefs of its Fairfax and Arlington-Alexandria news bureaus.

As a reporter for The Washington Star and now The Post, Hiatt, 27, has covered Fairfax for almost two years. His work has included extensive day-to-day coverage of local government and in-depth investigative assignments, including articles on the proposed Springfield Bypass that ultimately led to the resignations of three members of the State Highway Commission.

Joining Hiatt in the expanded Fairfax bureau will be staff writers Mary Battiata, Sandra Sugawara, Eve Zibart and Molly Moore. All five will be based in the Fairfax bureau, 4103 Chain Bridge Rd., Fairfax City. The phone number is 334-6350.

Bauer, 31, has covered Virginia for The Post for three years, reporting on both Fairfax County and three sessions of the Virginia General Assembly.

Among her major stories was an award-winning series on cable television controversies in Northern Virginia. She also wrote accounts last fall of how actions of state Sen. Nathan H. Miller, then the Republican candidate for lieutenant governor, promoted legislation that created millions of dollars in tax breaks for clients of his law practice.

Joining Bauer in covering the inner suburbs will be staff writers Michel Marriott, Leah Latimer, Paul Hodge, Philip Smith and Nancy Scannell. The Alexandria bureau is at Suite 310, 501 King St., and the phone number is 334-6568. An office in Arlington will be opened soon.