Organizers look to late April 2007.

The "Britain Rocks New York" tribute concert, which was planned for Sept. 27 at the Nokia Theater in New York, has been postponed until late April 2007.

According to sources, sponsors have asked for the concert to be put back to allow time to expand the event and confirm additional performers.

Organizers are hopeful of retaining the services of British pop singer Natasha Bedingfield and urban artist Lemar, who were booked to perform on the original date. The source says, "we're already talking to their management to try to work around their schedules."

As previously reported, the concert was created to mark the fifth anniversary of the 9/11 terrorist attacks.

The brainchild of British Memorial Garden Trust president Camilla Hellman, "Britain Rocks New York" was intended to raise funds to help support the creation and maintenance of a memorial garden at New York's Hanover Square, near ground zero.

Investment bank HSBC and BMW-owned car brand Mini were committed to the event as headline sponsors.