OMAHA, Neb. (AP) — The real estate firm owned by Warren Buffett’s Berkshire Hathaway conglomerate is now the nation’s largest.

HomeServices of America said Wednesday that it ranked first last year after its associates helped close 346,629 residential real estate transactions. The ranking comes from the Real Trends 500 industry trade report.

HomeServices’ Executive Chairman Ron Peltier says being the biggest company in the market helps it lower costs by developing tools and software centrally for its real estate professionals to use.

The Minneapolis-based company has grown both by attracting more agents and by acquiring other firms. The company includes Berkshire Hathaway Home Services, Real Living Real Estate and a number of other brands.

Home Services is part of Berkshire Hathaway, which is based in Omaha, Neb. Berkshire owns more than 90 businesses.