Wall Street faces intrusive new government oversight of trading after U.S. regulators issued what they billed as a stricter Volcker rule today, imposing restrictions designed to prevent blowups while leaving many of the details to be worked out later.

The Federal Reserve, the Federal Deposit Insurance Corp. (FDIC), and three other agencies are set to sign off today on the proprietary trading ban, which has been contested by JPMorgan Chase & Co., Goldman Sachs Group Inc., and their industry allies for more than three years. Agencies were proceeding with plans to release the rule in Washington even as a snowstorm forced the federal government to close.

Wall Street's lobbying paid off in part. Regulators granted a broader exemption for banks' market-making desks, on the condition that traders aren't paid in a way that rewards proprietary trading, according to the final rule released today. The regulation also exempts some securities tied to foreign sovereign debt. At the same time, regulators gave banks less leeway for bets considered hedges for other risks.