By Nick Mulvenney

SHANGHAI (Reuters) - Jamaican sprint queen Veronica Campbell-Brown was leaving no hostages to fortune on Thursday as she looked forward to her first 200 meters race of a season she hopes will climax in a third successive Olympic gold in the event.

The 30-year-old's reticence about making predictions was understandable given the closeness of the competition between the top women sprinters, particularly those from the dominant Jamaican and U.S. teams.

Campbell-Brown lost a tight 100 meters race in Doha last week, crossing the line just 0.2 seconds behind American Allyson Felix (10.92) with Jamaica's Olympic champion Shelly-Ann Fraser-Pryce a close third.

At the Shanghai Diamond League meeting on Saturday, Campbell-Brown will renew her rivalry with another American in Carmelita Jeter, who she beat down the home straight to win her first world 200m crown in Daegu last year.

Given her lack of competitive practice in the event, and perhaps the fact the Jeter has run the fastest time in the world this year (22.31), Campbell-Brown was not about to make any promises about her performance at Shanghai Stadium.

"This will be my first 200 meters since I competed in Daegu," she told reporters. "The objective going into this race is to see where I am at, very technical, and try and get my race together.

"I'm expecting very good competition not only from Carmelita but from all the other ladies because I try not to underestimate anyone.

"I go into all my races believing that everyone's going to run fast so I focus on what I have to do to get to the finish line."

Campbell-Brown's caution might also be a result of her failure to qualify at 100m for the Jamaican team for the Beijing Olympics four years ago, which denied her the chance to match compatriot Usain Bolt's sprint double.

Given that failure when she was the reigning world champion in the short sprint, Campbell-Brown is not taking anything for granted - let alone her place at a fourth Olympics.

"Over the next couple of weeks I'm going to be concentrating hard, running a few races and preparing for the Jamaican trials, where I'm hoping to make the team for the London Olympics," she said.

Despite the defeat to Felix, Campbell-Brown was encouraged by her performance in Doha.

"My race showed that I was in very good shape so I'm very excited about what's going to be happening later on this season and the competition among us females," she said.

Athletics fans will share her excitement about the many battles to come between the Jamaican and American women sprinters but Campbell-Brown was not giving up any pointers about who she thinks might come out on top.

"I wish I could know the result," she said. "I do know that it will be very difficult and I don't know whether it will be Jamaica and America on the podium.

"In track and field anything can happen and you really never know and the objective for me is just to concentrate hard, look forward to the competition, stay mentally focused and compete hard."

(Editing by Amlan Chakraborty)