The youngster turned 18 earlier this month but negotiations over his first senior deal have yet to reach a conclusion over wage demands, and other clubs are closely monitoring the situation.
"My advice would be sign the contract and stay at Liverpool unless there is something which makes him really uncomfortable," said the Frenchman. "We tried to look after Raheem as much as we could - he was really a long-term project - and I think he should commit."
Manager Brendan Rodgers remains confident an agreement will be reached and Comolli, who was at Anfield when Sterling broke into the first team under former boss Kenny Dalglish, added: "I really don't think money should be an issue.
"He is 18 and it is going to be one of many contracts he is going to sign and he is going to end up being a wealthy individual. The important contract, if you are money-orientated, is the one you sign when you are 31 not 18."
Liverpool are closing in on deals to sign Chelsea forward Daniel Sturridge and Blackpool's Tom Ince, who left the Reds as a reserve-team player in the summer of 2011 having rejected the offer of a new contract.
The Reds have been criticised for their handling of the Ince situation but Comolli, sacked by owners Fenway Sports Group in April, insists the issue was not in their control at the time and he backed the 20-year-old, who has scored 13 goals in the npower Championship, to return a better player.
"When I arrived (at Liverpool in November 2010) Tom was at the end of his contract," the Frenchman told talkSPORT. "One of the first things I did was meet him and his dad, and Paul was concerned the style of play (under Roy Hodgson) was not suited to his son, who was a quick winger.
"When Roy went I think we made four or five contract offers to Tom which he kept turning down...he didn't feel it was the right place for him to stay. The last offer would have made him the highest-earning player beneath the first team but to be fair to him I don't think money was the issue.
"We never released him. You don't release a player like this, you can't force him to stay. I am very pleased that he is doing well. If they buy him back, good for him and good for Liverpool."
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