GENEVA — The European Union said Monday that it would slash farm tariffs by 60 percent as part of a new global trade pact, a deeper cut than it has ever offered.

EU Trade Commissioner Peter Mandelson told reporters at the World Trade Organization that the offer was meant to kick-start a week of crunch talks on a new global commerce pact.

The 27-nation bloc has previously proposed to cut the tariffs by 54 percent.

“We’ve decided to help the negotiations this week get off to a strong start by raising the average cut in our agricultural tariff,” Mandelson said. “That is a very considerable improvement on our own part, but, of course, it’s light years away from any effort we’ve previously made in a trade round.”

But, he added, the offer was not a gift. It depends on emerging economies such as Brazil, India and China responding with improved offers on industrial tariffs.

Rich and poor countries have clashed repeatedly in the seven-year WTO talks known as the Doha round. Developing nations want more agricultural openings, while the United States, EU and others seek better access for their manufacturers and banks.

While the EU’s farm tariffs have been an issue of dispute — especially inside the bloc with countries skeptical of agricultural liberalization like France and Ireland — it is not clear how much pressure Brussels had been under from its trading partners.