Coastal Corp. extended its $2.6-billion offer for...

Coastal Corp. extended its $2.6-billion offer for Texas Eastern Corp. until March 10 and hinted it might top the $3.2-billion bid made this week by Panhandle Eastern Corp. . . . Potlatch Corp., San Francisco, said its directors have approved a $125-million project to complete modernization of its Lewiston, Ida., pulp and paper complex . . . Pacific Telesis Group’s board approved a dividend increase of 6.8%, to 47 cents from 44 cents per common share, payable May 1 to shareholders of record as of April 7.