* Stoxx 600 rises 0.3 pct
* Financial stocks among top gainers
* Insurance sector still up after Monday rally (Adds comments, more sectors)
LONDON, Sept 12 (Reuters) - European bourses continued their relief rally, opening higher on Tuesday after stock markets in Asia and in the United States hit record highs as worries about Hurricane Irma and North Koreas nuclear standoff eased.
All major trading centres and most sectors traded in positive territory as the pan-European STOXX 600 rose 0.3 percent, although some investors questioned how sustainable current markets levels are.
"Whether that equity reaction is Panglossian complacency or a sign of wonderful underlying fundamentals remains open to question," ING wrote in a morning note, adding that "even Category 5 storms can now be added to the list of things that 'Don't Really Matter"'.
Financial stocks were yet again among the top performers, with financial services and banking respectively up 0.7 and 0.6 percent.
Insurance firms, which fuelled Europe's rise on Monday with a roughly 2 percent jump, were again in positive territory, edging up 0.3 percent.
"The structure of today's open is typically 'risk-on"', said Pierre Martin, a senior sales trader at Saxo Bank, noting that the positive trend for banking stocks or automobile shares showed investors' moods were off geopolitical and climate worries and back to more positive corporate and macroeconomic news.
Volkswagen was up 0.5 percent after announcing a 20 billion euro plan on Monday to develop zero-emission vehicles and other constructors were also gaining ground, such as Peugeot which topped France's blue chip CAC 40 index with a 1.5% rise.
Novartis gained 0.6 percent as it reported that its biosimilar rituximab to treat blood cancers and immunological diseases such as rheumatoid arthritis was accepted for review by the U.S. Food and Drug Administration (FDA).
Among losers, French veterinarian pharmaceutical company Virbac sank 11.7 percent after cutting its full-year outlook.
British home builders were also under pressure with Taylor Wimpey losing 2.8 percent or Barrat Development 2.4 percent after a report highlighted risks to the sector, a trader said. (Editing by Raissa Kasolowsky)