The investment brings to more than $4 billion the total that AT&T has spent to upgrade its systems and services for over 3.5 million businesses since 2006.
The changes range from increasing U.S. broadband speeds to 24 times the slowest DSL speeds available over phone company copper wires to laying additional undersea cables to boost data flow capacity to Europe, Asia and elsewhere.
AT&T has previously announced plans to boost its mobile broadband capabilities, such as investing more in Wi-Fi and the next generation broadband technology called Long Term Evolution, so executives on the go can have smoother, easier online access. It will increase support for wireless devices, such as netbooks and electronic readers, for businesses.
AT&T has also indicated plans to delve more deeply into so-called cloud computing services as well, an increasingly popular option in which it would manage software applications and store data for corporate clients off-site.
The phone company, which is based in Dallas, said it plans to open another Internet data center in London and finish expanding centers in Ashburn, Va., and Piscataway, N.J.
Its shares slipped 15 cents to $26.16 in morning trading.