* STOXX down 0.2 pct after hitting 15 month high last week
* Oil stocks lead sectoral fallers as crude prices slip
* Mood dampened by G20 decision to drop free trade pledge (ADVISORY- Follow European and UK stock markets in real time on the Reuters Live Markets blog on Eikon - see cpurl://apps.cp./cms/?pageId=livemarkets)
By Danilo Masoni and Helen Reid
LONDON/MILAN, March 20 (Reuters) - European shares retreated slightly from 15-month highs on Monday with lower crude prices weighing on oil stocks and Deutsche Bank dragging banks lower one day before the start of its 8 billion-euro cash call.
The pan-European STOXX 600 index ended 0.2 percent lower, after hitting its highest level since December 2015 last week in a rally driven by better economic data, good company earnings and merger and acquisition activity.
But caution prevailed on Monday after the leaders of the world's biggest economies dropped a pledge to keep global trade free and open, acquiescing to an increasingly protectionist United States after a two-day meeting failed to yield a compromise.
The oil and gas index was the biggest sectoral loser, down 1.1 percent, as crude prices fell on rising U.S. drilling activity and steady supplies from OPEC countries.
The biggest drags on the index were Britain's Tullow Oil (LSE: TLW.L - news) , and oil majors Total (LSE: 524773.L - news) , Royal Dutch Shell (LSE: 0LN9.L - news) and Statoil (LSE: 0M2Z.L - news) , which fell between 0.7 and 2.4 percent.
Banks were also under pressure, down 0.6 percent.
Deutsche Bank fell 3.7 percent after the German lender disclosed terms of its 8 billion euro cash call, its fourth capital increase since 2010. The recapitalisation, aimed at funding a strategy overhaul, will start on Tuesday.
German luxury group Hugo Boss (IOB: 0Q8F.IL - news) was the top European faller, down 4.7 percent after GBL (EUREX: 1225249.EX - news) , the holding company of Belgium's richest man, Albert Frere, released full-year results on Friday with no holding in the firm - dashing rumours of a stake that had boosted the stock last month.
"Shares (Berlin: DI6.BE - news) are virtually unmoved on the announcement ... as investors wait for what's expected to be a fairly downbeat set of annual results in May," said Neil Wilson, senior market analyst at ETX Capital.
Top gainer in Europe was the frozen baked goods maker Aryzta , up 5.1 percent after Berenberg upgraded its rating on the stock to 'buy', saying the company's change of senior management and review of its holding in French frozen food retailer Picard were signs it was turning a corner.
Ingenico (Paris: FR0000125346 - news) rose as much as 4.5 percent before turning lower by 3.1 percent, in heavy volume, after Atos (Paris: FR0000051732 - news) formally denied a report it was preparing an offer for the French payments company. (Editing by Catherine Evans and Susan Thomas)