Graeme Smith has stepped down as South Africa's Twenty20 captain with immediate effect and will give up the one-day leadership as well after the 2011 World Cup. He will stay on as Test captain and is available for selection in all three formats. Smith announced his decision at a press conference in Johannesburg on Wednesday.

"There are several reasons why I have made this important career decision," Smith said. "I am going into my ninth season of international cricket - eight of which have been as captain. It is my intention to play for another five or six years and I know in my heart that I can only do that if I give up some of my current responsibilities."

Longevity was one of the main things on Smith's mind during the South African off season, during which he, "set some challenging personal goals for the future." He would only share a few of those aims, one of which is to "be around for much longer as a player," and the other, to win a World Cup.

Smith led South Africa in the 2007 edition of the ODI World Cup and in three World Twenty20s. The team failed to reach the final of any of those events, although they reached the semi-final stage twice. Speculation was rife that he would step down in May this year, after South Africa finished bottom of their Super Eights group at the World T20 in the Caribbean.

The pressure of filling a barren trophy cabinet was expected to become too much and Smith fuelled the fire himself when he posted a cryptic message on Twitter on July 20. "Captaining South Africa is an honour and a privilege! And I'm so lucky to have had the opportunity. Thank you all for your support." He confirmed that the idea of stepping down was "going through my head for a while," but he did not isolate that tournament as the reason for this decision.

The team's Caribbean crusade was also the first full series Smith completed in 2010, after a string of arm and hand injuries forced him out of limited overs matches, such as during the India tour. He took no part in South Africa's ODIs in Australia in the 2008-09 season because of a broken hand and a tennis elbow condition kept him out of another ODI series in 2008, against England. Johan Botha captained the team on those occasions.

Despite being an absent captain in ODIs for much of the last two years, Smith dismissed the idea that the shuffling of the armband led to his decision. In fact, he felt his philosophies prevailed during those times. "My leadership style was to create an environment where the team could perform without me. There was never any problem when I returned. All the players were decent to me when I returned from injury and I just gelled back into captaincy."

Smith believes he created an ideal environment for other players to take on roles of responsibility. "It has always been my philosophy not only to make the Proteas [South Africa] the best team we can possibly be but also to enable the players to grow both as cricketers and as people. I believe we have now reached the stage where there are several players emerging within the squad to take on leadership roles."

It's for this reason that Smith chose to make his announcement now and not closer to the World Cup. He hopes it will give the administrators and players enough time to prepare for a new leader. "It is absolutely vital that we maintain continuity in a World Cup season and this major competition also concludes the current cycle of limited overs cricket. I also feel that making the announcement now will provide the time and development necessary to ensure a smooth transition."

Gerald Majola, CEO of Cricket South Africa (CSA), who was present at the press conference, felt Smith had given the administrators enough time. "He is leaving us when there are youngsters who can take up a leadership role, he is not leaving us in the lurch." Majola said CSA have been working on a succession plan for a while and they will announce the new Twenty20 captain next month.

The frontrunners for the job are Botha in the ODI role and AB de Villiers for T20s. Smith refused to comment on who he thought should take over but he did say that he would be willing to work with whoever was selected. Just like Shaun Pollock, who played under Smith after being stripped of the captaincy, Smith said he will play under a new captain without interfering. "I think it's very important to allow a person to find his feet and grow. I would like to add value because I think a senior player's role is a crucial one. I took over at a young age and Polly still played in the team and we were able to form a good relationship, so I learnt from a good man."

He has already demonstrated his ability to play under someone else. During the IPL, Smith played for the Rajasthan Royals under Shane Warne with much success. Smith's stepping down from the captaincy role in Twenty20s in unlikely to have an impact on, or be connected to, his appearance in the cash-rich league, but Smith left the door open for any possibility. "I don't know (about the IPL). We don't know what's going to happen with the IPL in future, but all I'll say is that I am committed to South Africa."