Starwood has extended registration for its Night after Night promotion from March 31 to April 15, 2009 and 250 SPG properties are offering an additional 500 bonus points per night.

To recap the bonus offer, SPG members can register for SPG’s Night after Night promotion and earn bonus points for every stay completed between Jan. 7 and April 30, 2009. Guests can earn 500 bonus points per eligible night plus an additional 5,000 points for every 10th night during the promotional period. Stay 10 nights and you’ll earn a total of 10,000 bonus points.

Now, if you stay at one of 250 properties offering an additional bonus, you’ll earn 500 more bonus points per night. Which means if you stay 10 nights at participating hotels you’ll earn a total of 15,000 bonus points. Properties offering the extra 500 points include The W San Francisco, Sheraton Denver Hotel, W Atlanta, The Westin O’Hare, Le Meridien Bora Bora and many more.

Members who have registered for the Night after Night promotion are automatically registered in the new bonus offer. Visit http://www.spgpromos.com/nights if you have not yet registered.