Independent directors of Minemakers Limited (ASX: MAK) said Thursday that it was making a conditional scrip offer of one Minemakers' share for every 10 shares in Bonaparte Diamond Mines NL (ASX: BON).Bonaparte is an exploration and mining company with its principal projects in Namibia and South Africa. The company announced earlier this week that it was withdrawing from diamond exploration --because of the state of the market--to focus on its marine phosphate project in Namibia.It holds a 42.5% interest in the Sandpiper-Meob offshore licences where an initial JORC-compliant Inferred resource of 196.1 Mt at 15.8% phosphate. A further resource update was expected by late this month.

Minemakers' flagship is the Wonarah rock phosphate project in the Northern Territory where there is a JORC-compliant inferred resource of 461 Mt @ 18.8% P205. The company aims to be in commercial production early in 2010. The company also has a portfolio of tin and tungsten, fluorite, salt and iron ore projects in Australia.Minemakers said that if its bid for Bonaparte was successful it would pave the way for the company becoming a world-significant producer of phosphate.In view of the Boards of both companies having three common directors, the Corporations Act requires that Bonaparte produce a Target's Statement which will include an opinion from an independent expert as to whether the Minemakers' offer is fair and reasonable, Minemakers said.The common directors are Ted Ellyard (chairman of Bonaparte), Andrew Drummond and Dennis Wilkins, who is the finance director of both companies. Each has indicated he will accept the Minemakers offer in the absence of a superior proposal and the independent expert concluding that the offer is reasonable. Their collective shareholdings comprise about 11.7% of the issued shares of Bonaparte.In a separate statement Thursday, Bonaparte said its diamond operations at the Savanna mine in South Africa have been placed on care and maintenance due to the prevailing weak market for rough diamonds.Minemakers' Chairman George Savell said: This is a logical and value-adding proposal for both our shareholders and Bonaparte's shareholders, given the common strength of phosphate projects in both companies and the expertise we are gaining from our fast-track development of Wonarah.We believe that the integration of the companies will provide a strong strategic fit leading to improved scale and penetration of the world market for the supply of rock phosphate. The consolidation of phosphate interests will create opportunities to access new sources of development capital and to optimise marketing and sales arrangements worldwide.The Minemakers' offer is subject to certain conditions including a 50.1% minimum acceptance condition, a no material adverse change condition and a no-prescribed occurrences condition. The full conditions of the offer will be set out in the Bidder's Statement.In an earlier corporate life both Drummond and Ellyard were directors of Zephyr Minerals which in the 1990s was exploring for marine diamonds off the Kimberley coast of Western Australia, but that quest lost traction.Later both played a key role in luring former South African marine diamond specialist Mike Woodborne to head the then new Bonaparte company to take up some of the former Zephyr offshore areas in the Kimberley's Bonaparte Gulf and to also undertake a marine quest off Namibia.The Bonaparte Gulf quest failed quickly and Bonaparte began recovering diamonds off Namibia with another company in a joint venture that lapsed with the failing price for diamonds. However, Bonaparte discovered some significant marine phosphate deposits.A statement issued by independent Bonaparte directors advised shareholders to take no action at this stage.