Olympic 5,000m champion Gabriela Szabo has been added to the field for Friday's Norwich Union Grand Prix at Crystal Palace.

The Romanian will take on newly-crowned European champion Marta Dominguez and world number three Berhane Adere of Ethiopia.

Commonwealth 100m champion Kim Collins and Olympic long jump champion Heike Drechsler have pulled out of the meeting.

"Kim had an invitation but has not taken it up for personal reasons," said a UK Athletics spokesperson.

"Heike has perhaps not been competing to the standards she has set herself, and maybe felt she could not do herself justice on Friday."

Drechsler finished fifth in the recent European championships and has been struggling for form.

Among the high-profile athletes who will be in action are Olympic 1500m champion Noah Ngeny in the mile and 5,000m champion Million Wolde in the men's 3,000m.

A total of 33 current and reigning world champions will feature, as well as past Olympic champions Allen Johnson in the 110m hurdles and Gail Devers in the 100m.