Singapore Telecommunications, known as Singtel, said it would pay $321 million for Redwood City, Calif.-based Amobee, which is owned by a raft of venture capital and cellular phone companies.

"Beyond mobile advertising, through banner ads, there are opportunities to include targeted deals and coupons as well as loyalty rewards programmes for customers. SingTel fully intends to harness these opportunities to become not only the leading mobile advertising company in Asia Pacific, but also among the top three worldwide," the company said.

The acquisition is part of a broader restructuring at Singtel designed to respond to changes in the wireless-services industry. The company, which has 434 million customers, has replaced geopgrahic divisions with three new units.

An information communication technology division will focus on corporate customers; a consumer unit will oversee retail cellular and data activities; while Digital Life will work to expand its services.

Amobee was founded in 2005 by Zohar Levkovitz, who was replaced as CEO by Trevor Healy, chief innovation officer of Telefónica SA's European activities, last summer. The company feeds tiny ads to mobile phones and connected gaming devices, regardless of operating system.

Although the mobile advertising market is currently worth about $4 billion, Singtel said it will explode to $15 billion in 2015 as consumers snap up smartphones and tablet PCs such as the iPad. Amobee has received unspecified funding from Sequoia Capital LLP, ACCEL Partners, Globespan Capital Partners, Cisco Systems Inc., Motorola Ventures, Telefónica and Vodafone Group plc.

Singtel has been looking at the opportunities created by mobile phones for years and, in 2010, set up its own Singtel Innov8 venture fund. The company endowed the fund with S$200 million ($159.1 million).

It's already invested in a variety of network- and consumer-related startups such as Singapore's Bubble Motion Inc. messaging company; Cupertino, Calif.-based targeted advertising company Baynote Inc.; and Sunnyvale, Calif. Wi-Fi networking company Ruckus Wirelss Inc.

Singtel said it expects to close the Amobee acquisition in June.

The Singapore phone company is 55%-owned by Temasek Holdings Pte. Ltd., a Singapore government investor.

In addition to its activities in Singapore, its Singtel Optus Pty. Ltd. is Australia's No. 2 wireless provider. It also has about a third of Bharti Airtel Ltd., India's biggest phone company.