Jirayuth Roongsrithong, CAT's president, said the two state telecom enterprises are now drafting a memorandum of understanding, with a contract signing expected soon.

However, TOT executives are worried such a 3G roaming agreement could scotch negotiations between TOT and Advanced Info Service (AIS) on a 3G co-base station plan.

Mr. Jirayuth said TOT has shown an intention to roam its 3G network on the 1900-megahertz frequency with CAT's 3G network on the analogue 850-MHz spectrum using the same high-speed packet access plus (HSPA+) gear.

Network roaming would enable the two agencies to provide 3G services at speeds of up to 42 Mbps for faster and more consistent network access.

Mr Jirayuth acknowledged that True Corporation would also reap benefits from a roaming agreement, as CAT reserved 80 percent of its 3G network capacity to it under its contract conditions.

But he said TOT would likely gain more benefits because the government plans to expand its 3G network to 15 provinces in the first year.

With the acting National Broadcasting and Telecommunications Commission stalling imports of 3G network equipment, CAT and True are facing further delays to 3G network construction.

CAT plans to install 5,000 HSPA base stations nationwide in the first year, while TOT's 3G network expansion project requires installation of more base stations than CAT due to the latter's frequency type.

Suphachai Chearavanont, True's president and chief executive, said roaming would benefit both CAT and True.

He said True is ready to purchase network capacity to provide 3G HSPA+ or 4G-compatible services. The subsidiary True Move H, through its 3G operating unit Real Move, is preparing to upgrade its 3G high-speed packet access network on the analogue 850-MHz frequency to 3G HSPA+ technology, enabling it to provide 4G-compatible speeds of up to 80 Mbps.