Dan Gilbert's Rocket Companies plans to buy the online real estate brokerage firm Redfin, a $1.75 billion deal that would expand Rocket's presence in all things residential real estate. The all-stock deal was announced Monday morning and, pending approval by Redfin shareholders, is expected to close in the second or third quarter.

Redfin is being acquired in an all-stock transaction that values the real estate listing platform at $1.75 billion.

Rocket Cos. is pushing deeper into the property market with a deal to buy Redfin Corp. that values the real estate listing site at $1.75 billion.