FRANKFURT, April 28 (Reuters) - German engineering services group Bilfinger is nearing a decision on the future of its Building and Facility unit after the field of serious contenders has narrowed to one, several people familiar with the matter said.

The company remains in talks with buyout group EQT, which has offered to buy the unit for less than 1.4 billion euros ($1.6 billion), the sources said.

It may, however, still opt for keeping the business, which last year posted earnings before interest, taxes, and amortisation (EBITA) of 148 million euros on 2015 sales of 2.9 billion euros.

Bilfinger and EQT declined to comment.

Bilfinger, 26 percent owned by activist investment firm Cevian, said in January it was considering selling its most profitable businesses, raising the prospect of investors getting a return from the struggling group but leaving it dependent on a volatile energy market.

Bilfinger had said it intended to update markets on its strategy in mid-May. Since then, its chief executive unexpectedly quit, raising fresh questions about its future direction.

Other initial suitors, such as Engie, JLL and CBRE, are no longer actively pursuing the asset, the sources said. ($1 = 0.8837 euros) (Reporting by Arno Schuetze, Alexander Hübner and Georgina Prodhan; Editing by Christoph Steitz)