The real estate development unit, Hong Kong International Construction Investment Management Group Co Ltd (HKICIM), pledged 1.4 billion shares with PAG Holdings Ltd, which owns alternate investment management firm PAG.

The fundraising comes on the heels of a deal to sell two Hong Kong land parcels to Henderson Land Development Co for $2 billion.

In recent months, other HNA units including Bohai Capital and HNA Infrastructure have pledged company shares to raise capital as the conglomerate seeks to alleviate strains caused by a $50 billion acquisition spree.

Many of HNA's listed companies are also known to have pledged shareholdings as collateral to leverage assets in the past few years.

HKICIM said in a filing it had pledged the shares on Feb. 14 but did not disclose terms of the deal. Based on its Feb. 14 closing price, a 41 percent stake would have been valued at about HK$3.1 billion (280 million pounds).

While levels of borrowing by share pledging do vary, typically lenders advance funds worth 30 percent of the shares pledged.

The HNA unit said it may pledge more shares as collateral to PAG if the loan-to-value ratio falls below a prescribed threshold. A spokesman for PAG declined to comment.

(Reporting by Donny Kwok Editing by Sumeet Chatterjee and Edwina Gibbs)