SHARES in information company Thomson Reuters PLC fell on their debut on the London Stock Exchange yesterday.

The newly merged company also announced it may buy back up to US$500 million worth of equities this year as trading began in London ahead of dealings starting later in Toronto and New York.

After hitting the boards at 1,700 pence (US$33.66), the stock touched a low of 1,612 pence before recovering some ground to trade at 1,687 pence midmorning.

Collins Stewart analyst Gareth Thomas said that the company has an overall portfolio of "excellent businesses," but added that its performance will be dominated by its large markets division which is subject to cyclical trading.

"We assume that given the fragile outlook for the financial markets industry, the risk to the markets division's forecasts is to the downside, and that's before factoring any execution risk from the merger," Thomas said, changing the brokerage's previous hold recommendation to sell.

"We see three negative risks to markets division's growth - merger execution risk, pricing risk and cyclical risk," he added.

ABN Amro also initiated the company with a sell rating, providing a target price of 1,500 pence. The brokerage also expects Thomson Reuters Corp to open lower when trading opens in Toronto later yesterday.

Tom Glocer, the former Reuters CEO who is now chief executive officer of Thomson Reuters, said the plans to buy back shares underscored the company's financial strength.

"We will manage Thomson Reuters capital structure and set our cash distribution policy so as to maintain a strong yet efficient balance sheet," he said.

Yesterday's listing are the culmination of a deal in which Thomson agreed to pay about US$15.8 billion for London-based Reuters.

With more than 50,000 employees and operations in 93 countries, the combined Thomson Reuters Corp will compete directly with Bloomberg News in financial news and information, with each commanding about a third of the market.

Glocer said that the merged firm would benefit from "the value created by more diversified revenue streams, a larger capital base and synergies resulting from the acquisition."