Russian Olympic champion and pole vault world record holder Yelena Isinbayeva has agreed a multi million-dollar contract with China's largest sportswear retailer Li Ning, several sources have told Reuters.

The agreement, worth $1.5 million annually for five years according to a person with knowledge of the offer, is significant because of the amount of money and the entry of a Chinese company into the athletics marketing world with a high-profile athlete.

"There is no athlete on the track circuit that earns that kind of money," said a person familiar with the negotiations.

That includes the base contract for Jamaican double sprint world record holder Usain Bolt, the source said. "It is out of synch in regards to the track market."

Bonuses for world records, world and Olympic championships could added to Isinbayeva's earnings, marketing experts said.

Isinbayeva, the IAAF female athlete of the year, has been under contract to Adidas, the world's second-largest sports goods maker.

Isinbayeva's agent, Daniel Wessfeldt, told Reuters by telephone: "On that I cannot comment at this point."

Officials for Li Ning, China's first national sports goods brand, were not immediately available. The company's website (http://www.lining.com/EN/home/index.html) contained no information about Isinbayeva.

The world record holder is scheduled to begin her indoor season this weekend at Donetsk, Ukraine, which would be her first opportunity to wear her new company's sports goods at a meeting.

She is also working on an agreement with another firm that would include a logo presence, a source said.

Li Ning was founded by the 1984 Olympic triple gymnastics gold medallist who last August lit the cauldron at the opening ceremony of the Beijing Games. It has around 10 percent of the Chinese market.

While Isinbayeva is its first high-profile athletics signee, the company has agreements with National Basketball Association (NBA) players Shaquille O'Neal of the Phoenix Suns and Baron Davis of the Los Angeles Clippers, according to O'Neal's NBA biography and a Li Ning news release about Davis.