DUBAI (Reuters) – Dubai government-owned port operator DP World plans to raise as much as $3.5 billion in an initial public offering by the end of next month, the Middle East Economic Digest reported on Saturday.

The Dubai government will sell up to 30 percent of its shares in the world’s third-largest container port business, the London-based weekly said in its latest issue, without making clear how it got the information.

DP World Chairman Sultan bin Sulayem told Reuters on Thursday the company had still to decide whether to proceed with an IPO or to finance expansion through loans, bonds or existing resources.

A person familiar with the plan told Reuters on Sept. 11 that DP World would sell 20 percent of its shares to the public this year to raise as much as $4.2 billion to finance growth.

A second person familiar with the plan said on Thursday that DP World was planning to sell a stake of around 20 percent but could not give the value of the deal.

A $4.2 billion share sale would make it the largest IPO in the Middle East, topping the $4.1 billion raised by Saudi Telecom in 2003. At $3.5 billion, the IPO would be the region’s second largest.

“Further details of any sale remain a closely guarded secret and the move is subject to approval by Sheikh Mohammed bin Rashid al-Maktoum, the ruler of Dubai,” the magazine said. The company considers an IPO among its financing options every year, Sulayem said on Thursday.

DP World, which last year bought UK-based port operator P&O for $6.8 billion, would list on the Dubai International Financial Exchange (DIFX), the person familiar with the situation, who did not want to be identified, said on Sept. 11.

The company is worth about $22 billion, that person said, adding the plan needed approval from the Dubai government.

Dubai Islamic Bank and Deutsche Bank, two of four banks advising DP World on a possible IPO, declined to comment on Thursday.

Other advisers are Merrill Lynch & Co Inc and Dubai-based Shuaa Capital.

Dubai set up the DIFX in 2005 to operate according to international regulatory standards in order to encourage local companies to sell shares to the public and for foreign companies to tap the region’s oil-driven wealth.

Dubai agreed last month to sell a 33 percent stake in DIFX to the Nasdaq Stock Market Inc under a deal that would give the U.S. bourse operator control of Nordic exchange company OMX.