China's leading online real estate portal SouFun is ramping up for its long-overdue initial public offering, according to a company source.

The insider confirmed with the Global Times that the website had planned to list its IPO on the New York Stock Exchange (NYSE) in June, explaining it was unclear as to why the float was not carried out as planned.

SouFun's IPO could be worth up to $300 million, which would make it the largest such listing by a Chinese mainland Web company this year, according to a report by the South China Morning Post Saturday.

"Based on a valuation of about $1 billion and a usual float of 25 percent of a company for such listings, SouFun's shares could be worth $100 million to $300 million," said the paper, quoting a banker working on the offering.

The portal could make its offering by the end of the year, the report stated, further indicating JP Morgan Chase, Bank of America, Merrill Lynch and USare also involved in the deal.

SouFun is 51 percent owned by Australia's Telstra Corp, which said last December it intends to sell its stake in SouFun as part of the latter's IPO plan.

Since June 2009, SouFun CEO Mo Tianquan has said on several occasions that an IPO in Hong Kong or US would be made in 2010.

SouFun's real estate information, consulting and online services cover 104 cities and has 20 million registered users.

Research firm CR-Nielsen estimates the nation's online real estate advertising revenue at 286 million yuan ($42.18 million) for the second quarter of this year, up 102.6 percent from the previous quarter.

SouFun's second quarter estimates are expected to reach 190 million yuan ($28.02 million), or 66.7 percent of China's total online real estate advertising revenue.

China Real Estate Information Corporation, SouFun's major competitor, merged with Sina Corporation's online real estate business on the completion of its Nasdaq IPO last October, when it raised $216 million for the project.