* EU makes improved agricultural offer including beef
* EU wants cars, dairy, public procurement access in return
* Chief negotiators to meet in Brussels on Friday (Adds Commission vice-president comments)
BRUSSELS, Jan 31 (Reuters) - The European Union has offered to open its markets to more beef from Latin American bloc Mercosur to try to conclude negotiations for what could be its most lucrative trade deal to date.
Ministers from the Mercosur countries Argentina, Brazil, Paraguay and Uruguay met EU trade and agriculture commissioners in Brussels on Tuesday to see how to drive forward negotiations stuck on the issue of beef.
The EU has raised its offer for beef access to 99,000 tonnes per year from a previous 70,000 tonnes, people close to the talks said on Wednesday, though it was not clear how much would be more expensive chilled meat and if it would be tariff-free.
The EU hopes an improved offer will encourage Mercosur to open its markets to cars and EU dairy produce more rapidly and allow EU companies to bid in public tenders.
The European Commission, which negotiates trade deals on behalf of EU countries, described Tuesday's talks as "constructive" and said chief negotiators would meet on Friday to push discussions on.
Commission Vice-President Jyrki Katainen told a news conference that negotiations had entered the "end game" and said he was optimistic a deal would be struck.
"Yesterday things moved forward and now we expect Mercosur to come back and give their view on how we could finalise negotiations," he said, adding both sides recognised a deal was politically and economically very important.
"It's always very, very difficult but if the political will is strong, as it is at the moment, I'm sure that we can get this exercise to the goal."
In terms of tariff reduction, it could be the EU's most lucrative trade deal to date, with the savings potentially three times greater than for deals with Canada and Japan combined.
EU farming nations such as Ireland and France, however, are worried their farmers will lose out and expressed concern when the initial offer of 70,000 tonnes was put forward in October.
European farms group Copa and Cogeca called the new offer unacceptable, with three-quarters of all beef imports - or 246,000 tonnes - already coming from the Mercosur countries, and said the sector was also facing uncertainty over Britain's exit from the EU.
"With 52 percent of Irish beef destined for the UK market, we cannot put further pressure on the EU beef market in a trade pact with the Latin American countries," its chairman Jean-Pierre Fleury said. (Reporting by Philip Blenkinsop; Editing by Robert-Jan Bartunek and Mark Potter)