US technology firms will now be allowed to export online services such as instant messaging and social networks.

Companies had not offered such services for fear of violating sanctions.

The US Treasury said exports would be allowed of services related to web browsing, blogging, e-mail, instant messaging, chat, social networking and photo- and movie-sharing.

Last year, software giant Microsoft barred users in five countries, including Iran, Cuba and Sudan, from using instant messaging services. People trying to use the service received an error message.