Qatari Diar, the property arm of Qatar's sovereign wealth fund, has settled with UK developer CPC Group in their dispute over a failed $1.5 billion London apartment scheme, the companies said in a statement.

Qatari Diar bowed out of its plans after Prince Charles, heir to Queen Elizabeth and longstanding critic of modern architecture, wrote privately to Qatari Prime Minister Sheikh Hamad bin Jassim al-Thani last year to protest about the Chelsea Barracks project's "brutalist" contemporary design.

London's High Court said last month that Qatari Diar, which is linked to the Qatari royal family, broke a clause in an agreement with CPC Group when it then shelved its proposals, and a CPC lawyer had said CPC would seek costs for the breach of contract at a future hearing.

"CPC Group and Qatari Diar are pleased to announce that they have agreed a settlement of the dispute between them arising from the proposed development of the former Chelsea Barracks site," the companies said in a joint statement.

"As a result, the litigation between them has been discontinued," the companies said. "CPC and Candy & Candy will no longer have any interest in, or involvement with, the former Chelsea Barracks site, which is owned entirely by Qatari Diar."

They said the rest of the terms of the settlement were confidential.

Charles' intervention angered many architects, who branded him a "meddling prince", and raised questions about his constitutional position. British royals have only symbolic power and usually steer clear of contentious issues.

The companies said property entrepreneur and CPC founder Christian Candy had also apologised on behalf of the UK firm to Qatar's ruler, Emir Sheikh Hamad bin Khalifa al-Thani, and the prime minister for any offence caused by the decision to litigate and allegations made during the proceedings. – Reuters