Oslo/Stockholm  - Norwegian cross-country ski star Marit Bjoergen and her Swedish rival Charlotte Kalla were considering not competing in the 10-kilometre classic event on Thursday at the world championships in the Czech resort of Liberec.

Bjoergen, 28, told broadcaster NRK on Tuesday that she had recovered from a stomach infection that she came down with over the weekend and on Wednesday would decide definitely if she would compete in the event.

"I feel OK and can eat again. But it is uncertain how much energy and strength I have lost," Bjoergen said.

Bjoergen also suffered infections prior to the Winter Olympics in Turin and the world championships in Sapporo.

Sweden's Kalla was more definite in her decision issuing a statement saying she would drop the 10-kilometre classic race preferring to focus on the sprint event.

Kalla, 21, said the "long ascent before the finish at Liberec was perfect" for her.

Sweden ski team coaches Magnus Ingesson and Joakim Abrahamsson said they "supported" Kalla's decision, saying "there was no doubt she had a chance of a better placing in the sprint than in the classic event". (dpa)