PRESIDENT VETOES STRIP MINING BILL, OIL TANKER PLAN
Pres Ford refuses to sign bill requiring 20% of oil imported into US be carried on US tankers; controversy on ship preference measure was increased by fact that some members of Cong who favored US maritime indus wanted to tie bill to foreign trade bill; Ford has strongly favored trade bill and Adm officials confirm that deal was made in which Ford would not oppose ship preference bill in Cong in order to get trade bill; Cong and Adm officials say no compromise was made that Ford would not veto bill (M)