PRETORIA, South Africa (AP) -- Oscar Pistorius will try to appeal his murder conviction in South Africa's highest court, his lawyer said Tuesday, possibly extending a legal battle that began nearly three years ago when the double-amputee Olympian shot girlfriend Reeva Steenkamp to death in his home.

As Pistorius sat in the dock in a wood-paneled courtroom, defense lawyer Barry Roux unveiled the plan to take the sensational murder case to an 11-judge court known for abolishing the death penalty and affirming basic human rights after the 1994 end of white minority rule in South Africa.

If the Constitutional Court chooses not to hear the case, Pistorius will be back in a lower court on April 18 for the start of a sentencing process, meaning he will remain under house arrest under bail terms announced Tuesday for at least the next several months.

Pistorius had already been living under restrictions at his uncle's home in Pretoria since October after serving one year of a five-year prison sentence for manslaughter. That conviction, however, was thrown out last week when an appeals court convicted the former track star of murdering Steenkamp, a model who was in a toilet cubicle when her boyfriend fired through the door on Valentine's Day 2013.

Prosecutors said he killed her after an argument; Pistorius said he killed her by mistake, thinking there was an intruder in the house.

On Tuesday, Pistorius was granted bail of the equivalent of $692 in South African currency - he paid an amount 100 times higher when he first appeared in court for the shooting, though he was not placed under house arrest at that time.

Judge Aubrey Ledwaba also instructed that Pistorius be placed under electronic monitoring and may only leave his uncle's home between 7 a.m. and 12 p.m.

Bail is often denied in cases where a conviction is overturned for a harsher verdict, but Pistorius' compliance with previous bail and house arrest conditions may have influenced the judge's decision, said Manny Witz, a South African legal expert.

At the Constitutional Court, Witz said, Pistorius' lawyers could try to argue that the Supreme Court of Appeal convicted him of murder based on a factual finding when it questioned whether Pistorius really thought he was in danger on the night he shot Steenkamp.

In South Africa, appeals must be based on questions around the interpretation of the law, rather than questions based on facts surrounding a case.

Prof. Stephen Tuson at the Wits School of Law in Johannesburg said there was no guarantee that the Constitutional Court would hear Pistorius' case even though it has the authority to hear any matter, including those deemed to be non-constitutional.

The April 18 date for sentencing will allow the Constitutional Court time to decide whether it will take Pistorius' case, said prosecution spokesman Luvuyo Mfaku. The defense has 15 days to submit appeal papers to the court, he said.

Prosecutor Gerrie Nel was doubtful about Pistorius' appeal prospects.

''We're not convinced that the accused has made out a good case and that his application to the Constitutional Court will be successful, but we acknowledge that he has the right to bring such an application,'' said Nel.

The appeals court had said that regardless of who was behind the door, Pistorius should have known someone could be killed if he fired multiple times. Under South African law, a person can be convicted of murder if he or she foresaw the possibility of someone dying through their actions and went ahead anyway.

Earlier, the state argued that Pistorius may try to flee, and asked for strict bail conditions but did not say he should be sent back to prison before sentencing. Under the bail terms, Pistorius may not travel further than a 12-mile (20-kilometer) radius from his uncle's mansion and must hand over his passport to the police.

The minimum sentence for murder in South Africa is 15 years, though a judge can reduce that sentence for what the law describes as exceptional circumstances.

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