ECOLAB <ECL> STARTS BID FOR CHEMLAWN <CHEM> Ecolab Inc said it has started its previously-announced tender offer for all shares of ChemLawn Corp at 36.50 dlrs each. In a newspaper advertisement, the company said the offer and withdrawal rights expire April 20 unless extended. The ChemLawn board has approved the tender and a merger at the same price that is to follow. Ecolab said the offer is conditioned on receipt of at least 5,325,000 shares. ChemLawn now has about 10.0 mln shares outstanding. Ecolab said ChemLawn has granted it a conditional option to buy all authorized but unissued and unreseved ChemLawn shares at 36.50 dlrs each. The option is exercisable in the event that another party were to acquire 20 pct or more of ChemLawn by means other than a tender offer for all shares at a higher price than Ecolab is offering. The company said if the merger agreement is terminated under certain circumstasnces, it will be entitled to receive 20 mln dlrs in damages from ChemLawn. Ecolab said officers and directors of ChemLawn have granted it options to acquire an aggregate of 2,535,435 ChemLawn shares or about 24.8 pct for the tender price, again unless a higher tender were to be made by another party. Waste Management Inc <WMX> had originally made a hostile tender offer of 27 dlrs per share for ChemLawn which ChemLawn rejected as inadequate. On Friday, Waste Management said it would raise its bid to 35 dlrs per share.