Google, the Internet company, is taking aim at internet telephone companies like Skype by introducing a new capability in its free web-based email service that allows users to make calls.

For the moment only users in the U.S. will be able to make calls using their Gmail account. Until the end of the year, making calls anywhere in the U.S. and Canada will be free of charge. Meanwhile, calls to the U.K., France, China and Germany will cost 2 cents a minute.

Currently, Google offers computer-to-computer voice and video chat services.

In an interview with BBC News, Craig Walker, Google's product manager for real-time communications, said "this is a real big deal because now hundreds of millions of Gmail users can make phone calls right from their Gmail page."

"They don't need to download an additional application or anything to start making really high-quality low-cost calls. For the user it means much more efficient and low-cost communications."

The link to the telephone service can be found on the left side of the Gmail page within the "chat" window. A "call phone" button will appear along with a number pad that lets users dial the number of the person they want to get in touch with.

Google announced that the money raised from international calls will finance free calls within the US and Canada.

"What surprised me was that they actually said they hope to make money off the calls... Normally Google is like 'We don't know how we are going to make the money' or 'We will make money down the way, don't worry about it' and this stands out as a big benefit that they get actual revenue early on," said Danny Sullivan, editor-in-chief of SearchEngineLand, a technology blog.

Skype, the most successful Internet phone service, has its number of registered users at 560 million. The company claims that 124 million users log in to the service at least one a month while 8.1 million are paying customers. The company is planning to put shares up for a public offering later this year.

Google hopes to launch the service to users around the world soon. "Skype is a well known company in this place and they are almost like a verb in the internet calling world in the way Google is with search. You Skype someone. So I think there is some inertia there to get over and I am interested to see how Gmail users respond... But you always have to worry when Google comes after what you do. They don't do things half way and bring a lot of resources to any problem they try to tackle. It doesn't mean you are doomed," said Tom Krazit, a senior writer at CNET.com, the technology news Web site.

"Google's product won't work on your mobile browser so Skype has an advantage there but I don't think it is a stretch to assume Google will come out with a mobile version pretty soon," Krazit added.

Google plans plans to attract non-Gmail users to try out the service. The company is currently negotiating with a number of university campuses and airports to install red telephone boxes around the country to give users the chance to make a call over the service.