North American stock markets look set to open lower Thursday over renewed terrorism fears. British authorities said they foiled a plot to blow up U.S.-bound airline flights.

Crude oil prices fell nearly US$1 a barrel after news of the thwarted attacks on airplanes led many carriers to cancel flights.

Light sweet crude for September delivery dropped 85¢ to $75.50 a barrel in electronic trading on the New York Mercantile Exchange by midday in Europe.

In economic news, the U.S. trade deficit improved slightly in June as record sales of U.S. farm products and other exports blunted the impact of soaring crude oil prices. The deficit for June dipped 0.3% to US$64.8 billion, which was still the fifth-largest deficit on record.

In today’s earnings news, Four Seasons Hotels Inc. said its second-quarter profits slipped to $9.1 million from a year-earlier $15.8 million.

Aeroplan Income Fund said that the Aeroplan Limited Partnership, a major travel rewards program in which the fund has a 24.7%, saw its second-quarter profit jump 25% to $31.8 million.

Biovail Corp. revised some of its product revenue forecasts after second-quarter profit soared to US$80.6 million from a year-earlier US$3.7 million.

In financial news, Bank of Montreal along with its BMO Nesbitt Burns and BMO Trust divisions were named as defendants in a $10 million, class-action lawsuit over disputed foreign currency costs charged to certain registered accounts.

European indexes dropped in early action.

The Canadian dollar opened at US 89.33¢, up 0.07 of a cent.

Overnight, Japan’s benchmark Nikkei 225 index fell 25.68 points, or 0.16%, to finish at 15,630.91 points on the Tokyo Stock Exchange.

In Hong Kong, the blue-chip Hang Seng Index fell 124.44 points, or 0.72%, to 17,222.14.

On Wednesday ,the S&P/TSX composite index gained 9.97 points, or 0.08%, to 12,008.15.

The benchmark index hasn’t closed above the 12,000-mark since May 12.

Seven of the 10 TSX main sub-groups were down on the session.

The S&P/TSX Venture composite index gained 15.02, or 0.57%, to 2,649.17.

In New York, markets were down as investors showed concern about a lagging economy despite strong corporate earnings news.

The Dow Jones Industrial Average closed down 97.41 points at 11,076.18, while the S&P 500 declined 5.53 points at 1,265.95. The Nasdaq Composite ended essentially flat, losing just 0.57 of a point lower to finish 2,060.28.