By Ed Ballard

LONDON--Goldman Sachs Group has begun the process of selling its stake in the company that runs many of the U.K.'s ports.

A consortium led by the investment bank's infrastructure fund bought Associated British Ports Holdings PLC, or ABP, for 2.8 billion pounds ($4.47 billion) in 2006 following a bidding war with Australia's Macquarie Bank Ltd.

In a statement to bondholders marking the formal start of the sale process, ABP Thursday said that Goldman's GS Infrastructure Partners and Infracapital Partners--an investor owned by U.K. insurer and asset manager Prudential PLC (PRU.LN)--are looking for a buyer for their 33.3% holding in the group.

"The company does not anticipate that this will result in any changes at an operational level," said ABP, which operates 21 ports around the U.K.

Canadian fund Borealis Infrastructure Management Inc. and Singapore's GIC Special Investments each own a third of the company.

Spokespeople for ABP, Goldman and Infracapital declined to comment further on the sale process.

In January, GS Infrastructure Partners sold its 49% stake in SSA Marine, one of the world's largest port operators.

Write to Ed Ballard at ed.ballard@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires