DUBAI (Reuters) – State-owned Dubai Ports World plans to sell shares in an initial public offering before the end of the year to raise as much as $4.2 billion to finance growth, a source familiar with the plan said on Tuesday.

DP World, which last year bought UK-based port operator P&O for $6.8 billion, plans to sell about 20 percent of its shares and list them on the Dubai International Financial Exchange

(DIFX), said the person, who did not want to be identified.

The company is worth about $22 billion, he said.

DP World has applied to the DIFX for a listing, the person said, adding the plan still needed final approval from the Dubai government.

“No decision has yet been made,” Mohammed Sharaf, DP World chief executive officer, told Reuters. “It is one of the many options we are considering.” He declined to elaborate.

DIFX Chief Executive Officer Per Larsson declined comment.

Makram Kubeisy, managing director of investment banking at Dubai-based Shuaa Capital, which is one of four banks advising DP World on a possible IPO, also declined to comment.

The other advisors are Deutsche Bank, Merrill Lynch & Co Inc and Dubai Islamic Bank.

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