Century 21 Peak, a residential real estate brokerage in Woodland Hills, has acquired an Inland Empire brokerage as part of its expansion in Southern California. The company has bought American Inland Empire R.E. Inc. in Upland, which does business as Weichert Realtors 24/7. The company hired Stephen Yeager, former chief executive of Century 21 Mexico and vice president of Century 21 South America, as manager to oversee the office’s planned growth. Sandy Kohler, who has been branch manager, will train existing and new staff. Century 21 Peak said it bought the business because it sees the Inland Empire as a booming area. Additionally, while Weichert is a residential brokerage, Century 21 said it plans to add commercial real estate services in the future. Starting a year ago, Century 21 Peak has bought a commercial real estate office in Brentwood, a residential brokerage in North Hollywood and a residential real estate firm in Granada Hills. Orange County is the next area under consideration for a future acquisition, Century 21 said. Century 21 Peak is an independent affiliate under the umbrella of Peak Corporate Network, also in Woodland Hills.