Former world number one Clijsters had planned to retire at the end of 2007 after playing a handful of tournaments, but brought her decision forward to Sunday, saying "the fire had died out".

Henin, who became the first player to claim three titles this season -- and her first on clay -- when she beat Alona Bondarenko 6-1, 6-3 in the delayed Warsaw Cup final on Monday, was full of praise for Clijsters.

"When I heard Kim planned to play only certain tournaments this year, I thought she would find it hard, because you have to be 100 percent focused on your game, so I think she made the right decision to bow out now," Henin told a press conference at the rain-affected second day of Berlin's WTA tournament.

"It was a bit of a surprise that she took the decision now, but it is a decision everyone should respect. Belgian and world tennis is losing a great champion for sure.

"We should never forget what Kim Clijsters has done for tennis.

"We virtually grew up together and played a lot of tournaments together, we have lots of respect for each other, but we were rivals.

"It was a good story for Belgian tennis, because we were so different in our styles.

"I wish her all the best for her new life after tennis, it is going to be a big change for sure."

Clijsters will marry Belgium-based American basketball player Brian Lynch in July, while Henin is focused on winning again on clay in Berlin before she begins the defence of her French Open title later this month.

"Playing here is what I need before the French Open, it is another chance to get used to playing on clay again.

"I am comfortable playing on clay now, but you do have to adjust your game slightly and get used to the difference. Not a lot of girls like playing on clay, but I enjoy it."