NEW YORK (Reuters) - US phone company AT&T Inc said yesterday it plans to invest about $1 billion this year to expand its global telecommunications network to reach more countries and bolster its business services.

Both AT&T and its biggest rival Verizon Communications are pushing to provide services to big corporations as consumers are increasingly disconnecting home phones.

Including the planned 2009 investment, AT&T said it had put more than $3 billion into bolstering its global network, since 2006. It said it serves about three million business customers.

About $32.5 billion, or roughly a quarter of AT&T's total 2008 revenue, came from wholesale and enterprise customers using the global network. Joe Lueckenhoff, senior vice-president for product management, said the investment was included into AT&T's original spending budget for 2009, and would involve expanding into new services and geographies rather than specific assumptions that demand increases for existing offerings.

"What it's not is growing volume on existing products in existing countries," he said in a telephone interview. "Its mixed between new capabilities and new countries."

For example, the company plans to expand to 31 countries from 15 for its secure high-speed data networking service based on Ethernet technology.