LONDON (Reuters) - Global financial information provider Reuters Group Plc launched on Monday a new communications tool, instant messaging, which it is giving away to clients as part of efforts to improve its competitiveness.

The launch of the new product, which has been under development for almost two years, follows a heavy fall in the company's share price last week amid concerns that it has lost market share to rival Bloomberg LP, whose own established messaging service has been seen as a competitive advantage.

The group said its Reuters Messaging service was being offered at no extra charge to customers of its premium information service, 3000 Xtra, and to users of Reuters Plus and Reuters BridgeStation, both of which focus on equities.

It is to be integrated into the latest version of 3000 Xtra next week and the others by the end of the year. The company plans to connect 175,000 users to Reuters Messaging by the end of 2002 and already has registered 25,000 users world-wide.

Developed in conjunction with software giant Microsoft Corp MSFT.O , it uses an open-technology standard to enable customers to communicate real-time using text messages among themselves as well as with non-customers.

"It's really important to us," Glocer said at the launch in London, adding that the next stage would be to incorporate real-time audio and video communications into Reuters Messaging.

He said the facility was designed to accommodate security and legal requirements of financial institutions -- which account for the vast bulk of Reuters' revenues -- and that it differed in several key respects to Bloomberg messaging.

"Our major international rival, Bloomberg, has a proprietary messaging system. You have got to take the (Bloomberg) box to get the messaging and it's essentially a fast email standard," Glocer added.

Bloomberg LP was not immediately available for comment but a spokeswoman was quoted by the Wall Street Journal as saying, "our instant messaging system will be evolved to stay competitive."

Reuters and Bloomberg are major rivals at the premium end of the financial information market, providing real-time news and data to the desks of brokers, bankers and fund managers world-wide. But tumbling markets have forced financial institutions to cut tens of thousands of jobs.

Last week, investment bank UBS Warburg said Reuters had lost market share over the past five years, estimating Bloomberg now took 40 percent of revenues in the mid-tier and premium end of the market and Reuters 32 percent. However, Reuters had almost twice as many screens in those areas of the marketplace, with 315,000 compared with Bloomberg's roughly 170,000, UBS said.

The bank's comments, accompanied by a downgrade of its rating on the stock, persuaded some investors to sell Reuters shares, which lost almost 10 percent last week.

Reuters shares were up 1.58 percent at 193 pence in Monday afternoon trade.