UPDATE 1-Int'l Paper selling lumber unit to Georgia-Pacific

Dec 13 (Reuters) - International Paper Co is selling its building products unit to Georgia-Pacific LLC for $750 million cash, a move designed to sharpen focus on its massive packaging business.

The sale had been expected since IP acquired the unit, which sells lumber and particle board for home construction, as part of its $3.7 billion buyout of smaller rival Temple-Inland earlier this year.

IP is the largest North American producer of corrugated packaging, commonly used to make shipping boxes. Amazon.com Inc is one of IP's largest customers.

The sale gives IP more cash to invest in the packaging business.

Georgia-Pacific will get the unit's 16 manufacturing facilities located primarily in southeastern and eastern United States, regions that are expected to see new home construction when the economy recovers.

IP expects the deal to close in the first quarter of 2013.

Separately, IP said it will change the way it reports its pension expenses by reporting operating earnings that don't include the charges.

DuPont, AGCO and other companies have announced similar moves with reporting operating earnings this week.