EU deepens probe of Thomson buy of Reuters

(Adds details from statement, background)

BRUSSELS, Oct 8 (Reuters) - The European Commission said on Monday it had opened an in-depth investigation into the proposed takeover of Reuters Group RTR.L by Canadian financial information company Thomson TOC.TO.

"The Commission's initial market investigation indicates that the proposed merger would raise serious doubts as regards adverse effects on competition in several markets of the financial information sector," it said in a statement.

The launch of the in-depth inquiry does not prejudge the final outcome of the investigation, the statement said.

The planned merger, a cash and share deal worth 8.9 billion pounds ($18.14 billion), would create the world's leading provider of news and data for professional markets.

The Commission said it now has 90 working days, until Feb. 25, to decide whether the takeover would significantly impede effective competition.

Thomson notified the deal to the European Union's top antitrust regulator on Sept. 3 and the Commission said initial checks showed that the deal raised competition concerns.

Those worries concerned the supply of financial information, such as data-feeds, access to specific financial information databases and real-time broker reports, and the provision of news services, the Commission said.