Ford Motor Co. expects a greater after-tax loss in the just-completed first quarter of 1981 than in the final quarter of 1980, when it lost $316 million. Ford lost $1.5 billion during all of 1980.

This prediction was revealed in a prospectus filed with the Securities and Exchange Commission for a $200 million issue of five-year notes by Ford Motor Credit Co.

Ford's pretax loss in the first three months was about the same as the fourth quarter, but net losses were worsened by increased taxes on foreign earnings and other accounting factors, it said.

The prospectus said Ford expects its second-quarter losses this year will be "substantially smaller" than in the first quarter.

Ford also declared a dividend for the second quarter of 30 cents a share on its outstanding stock, payable June 1 to stockholders of record May 1. The payout is the same amount paid since the third quarter of 1980.

Meanwhile, Chemical Bank reported a 54 percent year-to-year increase in first-quarter profits,

Chemical New York Corp., parent company of Chemical Bank, the nation's sixth-largest, said yesterday that its earnings increase was largely the result of a greater profit margin on loans.

Earnings totaled $50.2 million ($3.12) a share) compared with $32.5) million ($2.06) in the 1980 first quarter, which was a particularly weak one for the bank industry.