FRANKFURT (Reuters) - Bayer has entered exclusive talks with BASF on the sale of its Nunhems vegetable seeds unit to address antitrust regulators' concerns over its planned merger with Monsanto, the two companies said.

Any deal is subject to a successful closing of theproposed $62.5 billion acquisition of Monsanto, which Bayer hopes to wrap up in the second quarter, the German group said on Wednesday.

Reuters reported last week that BASF was in advanced talks to buy the vegetable seeds business for roughly 1.5 billion euros (1.34 billion pounds)including assumed debt, citing two people familiar with the matter.

Bayer already agreed last October to sell businesses worth 5.9 billion euros ($7.32 billion) to BASF, including glufosinate-based herbicides and seed assets.

The deals will help BASF, the world's fourth largest maker of farming pesticides, gain a foothold in seeds, a business it had previously shunned.

The first deal covered "essentially all" of Bayer's field crop seed businesses, and related development work, including the oilseed canola business in North America and Europe and the global soybean seed business.

The global cotton seed business will also go to BASF, but excluding regional units in India and South Africa.

Bayer said last week that once it is sure enough that regulators will give it the green light, it would raise fresh equity capital to fund the Monsanto deal, which will make it the world's largest maker of seeds and pesticides.

Bernstein analysts said in January the rights issue would likely be worth 5-8 billion euros.

People familiar with the matter told Reuters last week that Bayer was on track to win conditional European Union antitrust approval for the Monsanto takeover.

Bayer has said the U.S. review was not as far advanced as in the EU, but it was confident it would make progress there over the next few weeks.

(Reporting by Ludwig Burger; Editing by Arno Schuetze and Adrian Croft)

By Ludwig Burger

Stocks treated in this article : Monsanto, Bayer, BASF