African rivals Haile Gebrselassie and Paul Tergat will compete against each other in a marathon for the first time.
The 33-year-old Ethiopian and 37-year-old Kenyan, who have faced each other on the track for more than a decade, head the field for the London Marathon, organizers announced Thursday.
Two-time world champion Jaouad Gharib of Morocco and defending London champion Felix Limo of Kenya are also entered for the April 22 race in what organizers called "one of the highest quality men's fields ever assembled for a major city marathon."
Gebrselassie, a two-time Olympic and four-time world 10,000-meter champion, finished a disappointing ninth in London last year, but had strong results at the end of the year, reports AP.
He ran a personal best of 2 hours, 5 minutes, 56 seconds to win the Berlin Marathon in September, the fifth fastest of all time, and also won the Fukuoka Marathon in December.
Tergat, who set the world record of 2:04:55 in Berlin in 2003, finished second in London in 2001 and 2002. He pulled out last year with an injury.
Also entered are 2004 Olympic champion Stefano Baldini of Italy; 2006 New York City Marathon winner Marilson Gomes dos Santos of Brazil; Americans Meb Keflezighi and Khalid Khannouchi; and 2005 London champion Martin Lel of Kenya.