UPDATE 7-Thomson Reuters raises outlook, grows fastest since financial crisis

* 2019, 2020 results seen at upper end of guidance

* Organic revenue grows 4% in Q2

* TR will own 15% LSE stake, have seat on board

* TR expects to sell LSE stake "over time" -CEO

* Shares up 2 percent (Updates shares, adds analyst comment)

By Georgina Prodhan and Matt Scuffham

LONDON/NEW YORK, Aug 1 (Reuters) - Thomson Reuters Corp raised its sales and earnings 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.

The news and information provider also confirmed that, along with Blackstone, it had agreed to sell Refinitiv, which provides data and news to financial customers, to the London Stock Exchange in a $27-billion all-share deal.

Growth in the second quarter was driven by recurring revenues at all three of its biggest units - Legal, Corporates and Tax & Accounting - since the news and information provider sold a majority in its Financial and Risk business, now known as Refinitiv, to Blackstone last year.

Adjusted earnings of 29 cents per share beat the average analyst estimate of 18 cents, according to IBES data from Refinitiv.

Shares in the company, which hit an all-time high last week, rose as much as 2.2 percent in morning trading. The stock has risen 88 percent since last May, helped by a $10-billion share buyback and new product launches.

"Thomson Reuters is making nice progress in repositioning the business after the sale of Refinitiv," said Edward Jones analyst Matt Arnold. "It's showed up in the quarter through nice organic growth and profitability improvement."

In an interview, Chief Executive Officer Jim Smith said the launch of legal research product Westlaw Edge last year had been a key driver behind 4 percent organic growth at the company's legal division, its biggest business.

"It's been a very, very solid performer for us and continues to gain a lot of traction," he said.

The strong performance enabled the company to lift its guidance for 2019 and 2020 revenue growth and earnings to the upper end of its previous forecasts.

It now expects organic revenue growth of 3.5% to 4% this year, compared with 3% to 3.5% previously, and 4% to 4.5% next year, versus 3.5% to 4.5% before.

The company anticipates adjusted earnings before interest, tax, depreciation and amortization (EBITDA) of $1.45 billion to $1.5 billion this year, compared with $1.4 billion to $1.5 billion previously. It expects an EBITDA margin of 31% next year having previously forecast 30% to 31%.

Thomson Reuters will hold a 15-percent stake in the London Stock Exchange on completion of the Refinitiv deal, which is expected in the second half of 2020, the companies said. A Thomson Reuters representative will also sit on the LSE board.

Under the agreement, Thomson Reuters cannot sell its LSE stake for two years following completion of the deal. It can sell a third of its shares in each of the third and fourth years after completion, and the rest thereafter.

Smith told Reuters the company will decide whether to sell its shares as the lock-up expires.

"Over the course of time, we would likely see that investment shifted behind our core businesses," he said.

Smith said the deal would "create a great deal of value" for Thomson Reuters shareholders.

Thomson Reuters set aside $2 billion of the $17 billion proceeds from last year's Blackstone deal for acquisitions. The company has made three acquisitions so far and has about half of the funds left for more deals, Smith said in an interview.

"We're considering a number of further options but one can never predict the timing of M&A," Smith said.

(Additional reporting by Pushkala Aripaka and Patrick Graham Editing by Alexander Smith and Nick Zieminski)