Mart, the world's largest retailer, will offer its online customers the opportunity to sign up with Netflix at their current monthly subscription price of $12.97 for a year, and Netflix will promote Wal-Mart DVD sales to its 3 million subscribers. Blockbuster struck back by offering Netflix and Walmart.com customers switching to Blockbuster's online rental service two free months of rentals plus a free retail DVD of their choice. Customers changing to Blockbuster Online would be able to subscribe for the next year at their current walmart.com or Netflix price. Netflix charges $17.99 per month for renters to keep three DVDs at a time. Blockbuster charges $14.99 for the same thing but this week began testing a fee of $17.99. Walmart.com's customers have paid $12.97 to take out two DVDs at a time. In a statement, Blockbuster Chief Executive John Antioco reiterated his commitment to aggressively growing the online business to catch up with Netflix. Last week, Antioco was temporarily unseated as board chairman in a proxy fight waged by dissident shareholders unhappy, in part, with heavy spending on the online service. --More 2254 Local Time 1954 GMT