The Graf Report, commissioned by the government, also said at least 25% of the BBC's online content should be externally supplied by the end of 2006.
BBC Online should prioritise its coverage of news, current affairs and education, the report concluded.
And it stated that two governors should be appointed to regulate the material the BBC publishes online.
The report was commissioned by the government to see if the BBC had stuck to its original remit and to look at its impact on the commercial sector.
In response to this, the BBC's director of New Media and Technology, Ashley Highfield, said the following five BBC websites would now close:
The Pure Soap site
He said their closure was based on "the grounds that their market impact might be greater than their public value".
However, he added: "Importantly, he (Mr Graf) also says it cannot be proven that our online services have had a negative impact on the market and that it's unlikely that bbc.co.uk has eliminated effective competition across any large areas of online content."
Several BBC sites had already been shut down. One called /money was deemed to be duplicating information which could be found elsewhere, and others, such as /legacies, did not attract enough users to justify their cost.
Mr Graf described BBC Online as "one of the leading providers of online news and current affairs content", which was "entirely consistent with the BBC's broader purposes".
"It should continue to provide fair, independent (national and local) news and current affairs coverage," he wrote.
Culture Secretary Tessa Jowell said she found the review, by former newspaper executive Mr Graf, to be "authoritative and constructive".
She said she was looking to the BBC's governors to ensure BBC Online remains a key player in the "vastly different technological landscape" of the future.
Ms Jowell will decide if further action needs to be taken after October.
Julie Kirkbride MP, shadow Culture Secretary, said the Conservatives were "pleased the report recommends more scope for independent providers on BBC online".
And Don Foster MP, Liberal Democrat shadow Culture, Media and Sport Secretary, added: "The answer to Graf's analysis is not to introduce new governors but a new system of regulation for all public service broadcasters."
The BBC is to close its Pure Soap website
The BBC's governors welcomed the "thorough and insightful" report.
"His report contains a number of sensible recommendations about how the service should operate in the future and how it should be both managed and governed," they said.
Mr Graf said his aim for the report was to "give a fair and accurate portrayal of the BBC Online service to date, and to give a reasoned view on where we might go from here".
The review's other recommendations said there should be a "deliberate precautionary" approach to BBC online investment - if there is a "close call" between the public service benefits of a proposed BBC service and the costs involved, it should not be taken forward.
BBC'S 1997 ONLINE REMIT
To act as an essential resource offering wide-ranging unique content
To use the internet to forge a new relationship with licence payers and strengthen accountability
To provide a home for licence payers on the internet and act as a trusted guide to the new media environment
Hugo Drayton, chairman of the British Internet Publisher's Alliance (Bipa), which has been highly critical of the BBC's online operations, told BBC News Online: "We want a proper independent regulator, and a proper remit for BBC Interactive.
"Any new services being subjected to the same approvals process as radio or any other form of broadcasting."
The BBC's websites contain more than two million pages and reach up to 43% of the UK online population each month, according to the corporation's latest annual report (2002 - 2003).
The review, which included consultation with the new media industry and BBC online users, forms part of the charter renewal process which reaches its climax in 2006.
The rest of the BBC's digital TV and radio services are currently undergoing similar scrutiny.