Marking the first step in what could be a major change in Hollywood's relationship with Netflix Inc., Warner Bros. has struck a deal with the fast-growing online DVD subscription service that will prevent it from offering new releases until 28 days after they go on sale.

The studio is hoping that the four-week "window" will push consumers interested in watching movies at home to purchase the DVD. Warner already imposes an identical window on $1-per-night kiosk company Redbox and its competitors. Although its unilateral move against Redbox has led to a court battle, Netflix agreed to the 28-day window in exchange for improved financial terms, higher inventory levels and increased access to content for its online streaming service.

As plummeting DVD sales have shrunk the bottom line of studios in recent years, they have focused on Redbox and Netflix, the two fastest-growing segments of the home entertainment market, out of concern that they are drawing consumers away from purchases. Redbox and Netflix rentals generate the smallest profit margins for studios of any home entertainment transaction, and Blu-ray and DVD purchases are the most profitable.

"The 28-day window allows us to continue making our most popular films available to Netflix subscribers while supporting our sell-through product," Warner Home Video President Ron Sanders said in a statement.