Adds details from the release, regulatory filings

May 21 (Reuters) - Equity Residential EQR.N and AvalonBay Communities AVB.N have agreed to an all-stock merger to form a housing rental company with an enterprise value of $69 billion, the firms said on Thursday, strengthening their presence in key U.S. markets.

The companies said they have a 95% overlap in markets where they own rental properties, a concentration expected to improve margins by enabling neighborhood-based operations, centralized services and lower cost-to-serve.

The deal is expected to generate $175 million in gross synergies by the end of 18 months after completion, driven by reduced corporate overhead costs and property management expenses.

Under the deal, AvalonBay shareholders will receive 2.793 shares of Equity Residential common stock for each share they own.

On closing, expected in the second half of 2026, AvalonBay shareholders will own about 51.2% of the newly formed company and Equity Residential shareholders the rest.

A combination will also pave the way for a larger proprietary data set, which can improve AI-powered demand forecasting, the companies said.

AvalonBay CEO Benjamin Schall will lead the combined company. Equity Residential CEO Mark Parrell will retire after the transaction closes.