SINGAPORE (Bloomberg) - BHP Billiton, the world's biggest mining company, is giving up four floors in Singapore's central business district as it prepares to spin off much of its metals production, according to a person familiar with the matter.

BHP, which has about 230,000 square feet of office space at Marina Bay Financial Centre Tower 2, is looking to vacate about 100,000 sq ft, said the person, who asked not to be named as the discussions are private. The company will rent two floors with an area of about 40,000 sq ft at CapitaLand's new office tower CapitaGreen, the person said.

BHP plans to split off assets including its silver, manganese and aluminum operations into a newly formed company called South32 Ltd. to focus on larger businesses such as iron ore. BHP and South32 marketing teams will be based in separate offices in Singapore, according to an e-mailed response to queries from Bloomberg News.

A lease has been entered into for the CapitaGreen building, BHP said in the statement, without saying how much space it would take.

The miner is also considering consolidating office space at its Singapore headquarters at the Marina Bay Financial Centre, the company said, without providing specifics.

The average rent at Marina Bay Financial is about $12 to $13 per sq foot per month, according to Cushman & Wakefield Inc. At CapitaGreen, whose design widely uses greenery to make the building energy-efficient, it's about $10 to $11 for large tenants, according to the broker.

Monthly rents in Singapore's most sought-after office buildings reached $13.54 psf in the quarter ended Dec. 31, a 25 per cent increase from a year earlier, according to Savills.

Singapore prime-office rents posted a 14 per cent gain in 2014, the strongest in Asia, according to a report from broker Jones Lang LaSalle. That helped Singapore retain its spot as the most expensive regional office location after Hong Kong and Beijing.