* Pan-European FTSEurofirst 300 index down 0.1 pct
* Travel and leisure stocks top sectoral losers
* Partners Group rallies after update
* Renault, Vivendi gain helped by broker upgrades (ADVISORY- Reuters plans to replace intra-day European and UK stock market reports with a Live Markets blog on Eikon - see cpurl://apps.cp./cms/?pageId=livemarkets for site in development. See the bottom of the report for more details. Adds details, closing prices)
By Danilo Masoni and Atul Prakash
MILAN/LONDON, March 22 (Reuters) - European shares fell slightly on Tuesday as losses among travel and leisure stocks after the deadly attacks in Brussels were partly offset by gains in technology and autos.
At least 30 people were killed in attacks on Brussels airport and a rush-hour metro train in the Belgian capital, triggering security alerts across Western Europe.
"Geopolitical risk, including acts of terrorism which directly affect trade or movement, remains a significant risk factor to monitor," said Lorne Baring, managing director of B Capital Wealth Management in Geneva.
"In a period where there is suboptimal growth both in Europe and globally, combined with equity valuations that are no longer cheap, there exists an environment which is susceptible to shocks that can act as a trigger for falls in asset prices."
The STOXX Europe 600 Travel and Leisure index fell 1.8 percent, the top sectoral decliner, with shares in Ryanair , Accor, TUI and IAG all down by 1.5 to 3.8 percent.
Luxury stocks such as Ferragamo, LVMH and L'Oreal were also down by between 1.1 percent and 3.4 percent on concerns travel tourism, a key driver for their sales, could fall in the wake of the attacks.
The pan-European FTSEurofirst 300 index ended down 0.1 percent at 1,338.02 points, after falling as much as 1.6 percent earlier in the session.
The technology index was the biggest sectoral gainer led by software group Micro Focus, which rose 4.8 percent after agreeing to buy U.S. firm Serena Software.
French car maker Renault rose 3 percent, leading a positive auto sector, after HSBC added the company to its "Europe Super 10" list, citing its growth prospects and attractive valuation.
Vivendi rose 2.9 percent after Exane BNP Paribas upgraded the media group to "outperform" from "underperform" and raised its target price by 22 percent to 22 euros.
Partners Group rose 7 percent after the investment management firm proposed a higher dividend after full-year revenues rose 8 percent despite foreign exchange headwinds.
While investors remained focused on the events in Brussels for most of the session, some positive data releases provided encouragement about the region's growth prospects.
German business morale rose in March as the retail sector profited from buoyant consumer sentiment. Euro zone business activity ended the quarter on a higher note, suggesting extra stimulus from the European Central Bank may already be having a positive effect.
"The just-announced ECB stimulus, while not a game changer for growth, should neutralise some of the downside risks ... But today's ugly events in Brussels add further uncertainty to the outlook," said UniCredit economist Edoardo Campanella.
Among top gainers were car maker Renault
Today's European research round-up
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Mike Dolan, Markets Editor EMEA. (Editing by Mark Trevelyan)