3G network sharing will sweep through developed markets and have "profound implications" for mobile operators, vendors and regulators, new research warns.

A report from Analysys suggests that extensive 3G network sharing is now "inevitable".

"Despite a number of announcements made at the time of the 3G licence awards, the mobile industry was not ready to adopt extensive network sharing," said Dr Alastair Brydon, co-author of the report.

"Early interest in infrastructure sharing evaporated, and mobile operators chose to build and operate their own dedicated 3G networks. However, network sharing is back on the agenda."

Mobile operators face major expenses in the coming years, including investments in femtocells, LTE, broadcasting networks and fixed broadband, according to the analyst.

"As a result most operators will not be able to invest sufficient amounts quickly enough on their own to exploit 3G's full potential," he said.

Recent announcements of network sharing agreements between major operators such as T-Mobile and 3 in the UK indicate a change in attitude towards network sharing, Analysys believes.

The analyst firm pointed out that such network sharing can have considerable cost benefits.

For example, a network operator aiming to extend its 3G network to 13,000 sites could save $1bn in capital expense by reducing the need for new base station equipment and sites.

It could also save $1bn in operational expenses by sharing the cost of operating sites over 10 years. 2G network sharing could provide even greater cost savings.