Match referee Jeff Crowe found Smith in breach of Clause C1 for conduct contrary to the spirit of the game and he was penalised following a hearing in Trinidad, the International Cricket Council (ICC) said in a statement on Friday. The ICC said that because it was the player's second breach of this provision inside a year, the penalty was automatically upgraded from level two to level three.

"Graeme has been warned at a similar hearing last September when in breach and has been advised on numerous occasions that his over-rates are too slow, including being fined after the second ODI of this series," Crowe said.

Smith, as skipper, was also fined 30 percent of his match fee for the slow over-rates in Barbados. His team mates were fined 15 percent of their fees.

The 24-year-old Smith has 24 hours to appeal against the ICC's decision. Subject to appeal, the ban will apply with immediate effect.

Smith's previous breach was also against West Indies, in the ICC Champions Trophy in England last September.

South Africa have an unbeatable 3-0 lead in the five-match series.

Smith may be missing from action, but his side will be going all

out to complete an unprecedented clean sweep of a one-day international series against West Indies in the Caribbean when the last two matches of their best-of-five series are played on Saturday and Sunday.

"We have won the series, but it is a bit disappointing that we had to receive an over rate fine," Smith told reporters on the eve of the Queen's Park Oval double header.

"We will have to accept it. That's the rule. I do not know if I completely agree with a four-match ban, and so I will just have to live with it.

"I do not think I will appeal it though. That may be dangerous. I think it may be better for me to serve out the ban and get it over and done with, so I will take it on the chin and leave it to the International Cricket Council to review their rules and take it from there."

Former captain Shaun Pollock has been handed the responsibility of leading the side in the two matches, and Smith believes the intensity will still be there for the South Africans to play West Indies hard.

"We want to win all the games, but what may hamper us is one or two injuries that we have picked up," he said.

"It offers some of the other guys an opportunity to come into the side and perform well, and this often bodes well. Someone who has not had opportunity to play yet may come and perform well, so everyone is motivated to play in Trinidad."

He added: "We can't take West Indies granted. In ODI cricket, it takes one good performance from an individual to win a game, so we cannot take them for granted.

"We are looking to improve on our performance in Barbados because we did not play up to the best of our abilities - we scored about 20 or 30 runs short, and bowled two extra overs at least - and it cost us a fine for over rates, and made the match tight.

"