By Tommy Stubbington 

European shares rose Wednesday, spurred by gains on Wall Street where shares rallied to fresh record highs on Tuesday.

The Stoxx Europe 600 was 0.3% higher midmorning, building on a positive start to the second half of the year after Tuesday's 0.7% rise.

That came despite a set of euro-zone manufacturing indicators that showed a modest slowdown in June.

With economic data still pointing to a fragile and uneven recovery, European shares have been outshone by their U.S. counterparts since the European Central Bank last month introduced a package of easing measures including interest-rate cuts and cheap loans to banks.

"Since the ECB's June meeting, much of the postmeeting euphoria has reversed, the euro is higher, equities are underperforming," said Barclays analyst Jim McCormick.

"The ECB may need to eventually step up its efforts."

The central bank makes its July policy announcement on Thursday, but most analysts expect it to keep policy on hold for now after last month's fireworks.

The euro was a touch lower against the dollar at $1.3662 Wednesday, still above the level it traded before the previous ECB meeting.

Elsewhere in currency markets, the British pound edged to a fresh near six-year high of $1.7162 following Tuesday's boost from strong U.K. manufacturing data.

In the U.S., stock futures inched higher after closing at record levels Tuesday, indicating a 0.1% opening gain for the S&P 500. Changes in futures aren't necessarily reflected in market moves after the opening bell.

Back in Europe, France was a notable underperformer in equity markets, with the CAC-40 index flat.

Shares of a number of French telecom firms came under pressure after Orange SA said it has dropped plans for a potential merger or acquisition in France. The firm has been at the heart of intense merger speculation, notably tying it to smaller rival BouyguesTelecom, a unit of Bouygues SA.

Shares in Orange, Bouygues, Iliad SA and Altice all fell.

Also in the French telecom sector, Alcatel-Lucent shares climbed after the firm was raised to overweight from neutral by J.P. MorganCazenove.

U.K. online food retailer Ocado was the biggest riser on the Stoxx Europe 600 after an upgrade to hold from sell by Deutsche Bank.

In commodities markets, Brent crude oil was down 0.6% at $111.64 a barrel, while gold was also unchanged at $1,327.10 an ounce.

Write to Tommy Stubbington at tommy.stubbington@wsj.com