Goldman Sachs and Morgan Stanley are planning summer layoffs as Europe’s economic crisis batters the markets, The New York Post has learned.

Morgan Stanley plans to cut about 100 trading jobs internationally over the next few weeks. It is not known how many of those cuts will come from New York. Goldman Sachs officials said they are also likely to eliminate jobs if the slowdown in trading doesn’t reverse itself.

About 8.9 billion shares were traded on the Dow Jones Industrial Average in the first quarter, compared with 10.8 billion a year earlier, and 13.1 billion in 2010 and 24 billion in 2009.

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Sources say that Goldman is already thinning its middle-management ranks but could cut even deeper. Goldman already cut about 8.5 percent of its staff from 35,400 in the first quarter of 2011 to 32,400 in the first quarter this year.

Spokespeople from both firms declined to comment.

Industry sources say other firms, including Citigroup, may also cut staff.

Market forecasters estimate that Wall Street could see 10 percent and 15 percent more cuts in the next quarter. That would be an additional 5,000 or so financial sector jobs.

These layoffs come after Wall Street experienced one of its most severe series of jobs cuts in the past several years.

Besides the European financial crisis, new regulations are also targeting financial firms. Sources also report that Moody’s Investors Services are set to announce downgrades of investment banks in about two weeks, which could make it more expensive for some firms to operate.

Credit Suisse, Bank of America and Barclays also appear to be headed for layoffs, according to the Bryan Ellis Investing Letter.

Editor's Note: How You Lost $85,000 During the Last Decade. See the Numbers.