Bayer has been successful in its quest for US birth control specialist Conceptus, completing its tender off with a majority interest of 96.4%.

The company said it will now exercise a "top-up" option under which Conceptus will issue a number of shares to Bayer so that it holds more than 90% of the outstanding stock.

This will enable Bayer to gain full ownership of Conceptus without having to convene a general meeting of the latter's stockholders, it noted.

The total value of the deal, which gives Bayer access to Essure, a non-surgical, hormone-free permanent birth control method, amounts to around $1.1 billion.

"We are pleased with Conceptus stockholders' positive response to our offer. It demonstrates the outstanding perspectives opened up by this acquisition project," commented Marijn Dekkers, Bayer's chief executive. 

A merger between Conceptus - which is headquartered in Mountain View, California, and has a workforce of around 300 - and a Bayer subsidiary is planned imminently, the German drug giant said.