BRUSSELS (AP) — The United States and the European Union, which already enjoy the world's biggest business relationship, resumed talks Monday on a deal to further grow two-way trade and investment.

The negotiations are taking place against the backdrop of European pique over reported U.S. electronic espionage, and were delayed due to the U.S. government shutdown. But officials for both sides said the benefits of the proposed Transatlantic Trade and Investment Partnership are too great for the talks to be affected.

The week-long bargaining session in Brussels was expected to discuss services, investment, energy and raw materials, and regulatory issues.

Negotiators for both the Obama administration and the European Union say the expected payoff of the TTIP agreement is job creation and economic growth. The trade volume in goods and services between the two economies — representing almost half of global output — totaled 800 billion euros ($1.08 trillion) last year.

A deal, which would cover manufacturing, services and agriculture, could include a reduction in tariffs. But negotiators say the biggest boon, to business and consumers alike, could come from trimming the red tape that often makes it difficult to buy and sell across the Atlantic.

One European study has found that dealing with regulations and bureaucracy on the other side of the ocean can add 10 to 20 percent to the price of an imported item, like a car. TTIP could make it possible for a vehicle deemed safe for sale in Europe to be sold in the United States, or vice versa, without additional tests or adaptations being needed.

According to a study co-sponsored by the Atlantic Council, a Washington-based think tank, TTIP could create as many as 750,000 jobs in the United States. The European Commission estimates it would inject 120 billion euros (161 billion dollars) yearly into the economy of the 28-nation trade bloc, and lead to hundreds of thousands of new jobs.

"The TTIP would be the cheapest stimulus package imaginable," the European Commission's Directorate-General for Trade said in a report.

Frances Burwell, the Atlantic Council's director of Transatlantic Relations and Education Programs, said that as well as administering a welcome jolt to the American and European economies, TTIP could establish health and safety rules that would become standard not just for America and Europe, but for China and other rising economic powers.

"If you look forward, the U.S. and Europe in 20 years will be a smaller part of the global economy. We need to figure out ways to stay competitive," Burwell said an interview. "And also we need to figure out ways to reinforce the rules that have helped us to be competitive and protect the safety and security of our citizens in terms of the goods they buy, the foods they eat."

A first round of TTIP talks was held in Washington in July. Negotiators will return there the week of Dec. 16. At a minimum, the Europeans are hoping to be able to announce results on some issues by 2014.