* STOXX up 0.2 percent
* Optimism grows that U.S. protectionism shift is nuanced
* U.S. futures rise
* Political uncertainty weighs on Italian bourse (Adds, shares, context)
LONDON, March 26 (Reuters) - European shares opened slightly higher on Monday amid optimism the protectionist shift in U.S. trade policy may be more selective and tactical than first feared.
The regional STOXX 600 benchmark rose 0.2 percent, with Germany's export-sensitive DAX up 0.3 percent.
"Exemptions on steel/aluminium tariffs have already been granted for other important trade partners (Canada, Mexico, EU), which suggests the U.S. president is using this approach more for negotiating leverage rather than any real intention to start a global trade war", wrote Mike van Dulken, head of research at Accendo Markets, noting a "measured" and "nuanced" response from China so far.
Another sign of optimism could be found in the fact that E-Mini futures for the S&P 500 were up about 1 percent, after reports the United States and China had quietly started negotiations to improve U.S. access to Chinese markets.
Spain's IBEX was also up 0.2 percent, despite renewed tensions surrounding the political situation of the Catalonia region.
One exception was Italy's FTSE MIB, which retreated 0.2 percent as speculation grows the anti-establishment 5-Star Movement and anti-migrant League might explore an alliance to form a government.
The political uncertainty triggered a rise in Italian bond yields.
Italian banks, widely used as proxies to trade political risk in the country, suffered, with UBI Banca down 1.7 percent and Unicredit losing 0.8 percent.
Among blue-chips, the top-mover was Roche, up 1.2 percent, after it announced positive results for its immunotherapy Tecentriq in lung cancer patients.
The news helped the pharmaceutical sector post the best performance, up 0.8 percent.
In the broader market, Raiffeisen Bank rose 3.6 percent after Deutsche Bank lifted its target price for the stock, and Fresnillo gained 3.4 percent after an upgrade to "buy" from Goldman Sachs, which also added the miner to its "conviction list"
Smurfit Kappa suffered the worst fall on the STOXX 600, falling 2.6 percent after it rejected a revised takeover offer from International Paper. (Reporting by Julien Ponthus; Editing by Tom Pfeiffer and Mark Potter)