On Tuesday Keith Coleman, Google's product manager, said the company had introduced Gmail Chat, which allows users to quickly start instant message (IM) conversations with people they are emailing.

He said: "We wanted to make it easy to switch back and forth between IM and email, and let you keep a record. If you compose an email, with a single click, you can start chatting with them.

"The history of the conversation will be right in your inbox. Gmail Chat treats IM and email the same way, all saveable and searchable."

Gmail Chat is designed to "leave a nice trail, like email" but has an "off the record" feature that leaves no trace of selected exchanges, Coleman said.

"Sometimes IM conversations you have are private and sensitive. You click a link, and that means the chat won't be saved in your email account or theirs or anywhere in between."

The Silicon Valley-based internet search giant launched its new Gmail service for the English language interface early on Tuesday.

Gmail Chat service in other languages will be phased in during the next four to eight weeks.

Critical mass

Martin Reynolds, an industry analyst at Gartner consulting, said: "It makes sense to tie the two together. The question is does Google have enough critical mass in its Gmail base to drag people into their instant messaging."

"They [Google] make themselves indispensable on your desktop"

Martin Reynolds,
Industry analyst

Google's aim is to give internet users another reason to use its site and, hopefully, click on advertising links there, according to Reynolds.

Google revenues come from advertisers who pay the search engine "per click".

Reynolds said: "Google's goal is to build hooks into your computer. Not in a nefarious sense.

"They want you hooked to them in whatever way they can. In doing so, they make themselves indispensable on your desktop."

Advertising

Google's infrastructure enables it to rapidly launch services such as chat or maps, while it has proven skilful at targeting users with advertising that is not blatantly intrusive.

"The one thing they have to be careful of is not driving clicks to advertising sites just to build revenues," Reynolds said, alluding to industry concerns regarding 'click fraud'. "They have to be legitimate clicks."

Google has advocated for an "open federation" that would allow people using email or chat to connect with each other no matter which internet messaging service they use.