* 2019, 2020 results seen at upper end of guidance
* Organic revenue grows 4% in Q2
* Deal to sell Refinitiv to LSE agreed
* TR will own 15% LSE stake, have seat on board (Adds further detail on Refinitiv deal, EPS comparison to estimates, detail on TR stake in LSE and M&A)
LONDON/NEW YORK, Aug 1 (Reuters) - Thomson Reuters Corp raised its sales and core profit outlook for 2019 and 2020 on Thursday after reporting 4% organic revenue growth in the second quarter, which it said was its best since 2008 and ahead of its expectations.
Growth was driven by recurring revenues at all three of its biggest units since news and information provider sold a majority in its Financial and Risk business, now known as Refinitiv, to Blackstone last year - Legal, Corporates and Tax & Accounting.
The company said that it and Blackstone had agreed to sell Refinitiv, which provides data and news to financial customers, to London Stock Exchange in a $27 billion all-share deal.
Thomson Reuters will hold a 15-percent stake in the London Stock Exchange on completion of the deal, which is expected in the second half of 2020, the companies said. A Thomson Reuters representative will also sit on the LSE board.
A $10-billion share buyback and the launch of new products following the Blackstone deal have propelled Thomson Reuters stock 85 percent higher since May last year, and the shares hit an all-time high of C$90.04 this week.
"We believe we are well positioned for future growth, and now expect 2019 and 2020 revenue growth and adjusted EBITDA to each be at the upper end of the guidance ranges previously provided," Chief Executive Jim Smith said in a statement.
The parent of Reuters News had forecast 2019 revenue growth of 7% to 8.5% before the effect of currency, and growth of about half that pace in 2020.
For EBITDA (earnings before interest, tax, depreciation and amortisation), Thomson Reuters had forecast $1.4-$1.5 billion for 2019, up from $1.4 billion in 2018, and an EBITDA margin of 30-31 percent for 2020.
In the second quarter, revenue rose to $1.42 billion from $1.31 billion a year ago as Thomson Reuters gained from payments it received from Refinitiv for its news service, broadly in line with analyst consensus of $1.43 billion.
Adjusted earnings per share of 29 cents were ahead of analyst estimates of 18 cents, according to IBES from Refinitiv.
Thomson Reuters set aside $2 billion of the $17 billion proceeds from last year's Blackstone deal, for acquisitions. It agreed to buy two businesses in June and July for undisclosed fees.
(Additional reporting by Pushkala Aripaka and Patrick Graham Editing by Alexander Smith and Nick Zieminski)