SEATTLE — The Federal Trade Commission has filed suit against Zillow and Redfin, alleging the companies struck a deal earlier this year to eliminate competition in the online rental advertising market.

In a complaint filed Tuesday in U.S. District Court, the FTC said Zillow paid Redfin $100 million in February to dismantle its rental listings business, including platforms such as Zillow Rentals, Rent.com and ApartmentGuide.com.

“Zillow paid millions of dollars to eliminate Redfin as an independent competitor in an already concentrated advertising market—one that’s critical for renters, property managers, and the health of the overall U.S. housing market,” said Daniel Guarnera, director of the FTC’s Bureau of Competition.

The lawsuit argues the agreement effectively neutralized Redfin’s

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