Melbourne, Apr 17 (PTI): An Australian court today rejected an appeal of the Melbourne teenager who was sentenced to 13 years in jail for killing Indian student Nitin Garg, a crime which outraged public opinion in India and put the bilateral relations under stress.

The teenager, who was 15-year-old at the time of incident in 2010, had appealed claiming the sentence was 'manifestly excessive', given his extreme youth, guilty plea and unintentional nature of crime, Australian news agency AAP reported.

Justices Marcia Neave, Peter Buchanan and Bernard Bongiorno of the Victorian Court of Appeal rejected his plea.

Buchanan said the sentencing judge, Paul Coghlan, had struck the appropriate balance between the boy's age and the gravity of his crimes.

The teenager, whose name has not been revealed due to his age, stabbed 21-year-old Garg to death during an attempt to rob him of his mobile phone as he walked through local Park in suburb of Yarraville in January 2010.

After pleading guilty to murder and to a charge of attempted armed robbery, he was jailed by the Victorian Supreme Court for 13 years, with a non-parole period of eight years.

Garg's murder shook Australia's international education sector to its foundations and triggered a diplomatic storm between New Delhi and Canberra.

While sentencing the boy, the court noticed that Garg's killing was not racial motivated.

Justice Coghlan said he accepted the boy was remorseful and had no intention to kill when he went to the park.

He said Garg was "an innocent and random victim" and it was his presence in the park, not his race, that led to him being attacked.