Christina Aguilera's summer tour nixed

Christina Aguilera has pulled the plug on her planned summer amphitheater tour, with the pop singer claiming she's been stretched too thin to adequately prepare for the trek.

"Christina Aguilera's summer tour has been moved to 2011 due to prior commitments that the singer had made to her film, 'Burlesque,' and to the promotion of her new album, 'Bionic,'" tour promoter Live Nation said in a press statement. "The singer felt she needed more time to rehearse the show and with less than a month between the album release and tour date this wasn't possible."

Tickets for the outing just hit the market last weekend; Live Nation said refunds are available at the point of purchase.

Aguilera's outing was to open July 15 in Uncasville, CT, and was routed to visit 20 cities in a little over a month.

"Bionic" will hit stores June 8 in the US, and "Burlesque," which also stars Cher, is scheduled to reach theaters in November.