Women who buy United States Savings Bonds will no longer have to indicate whether they are "Miss" or "Mrs." on the bond, according to a new regulation issued at the express direction of Treasury Secretary W. Michael Blementhal.

The new policy thus gives women the option men have always had of keeping private their marital status on bonds if they so desire. The Secretary, in one of his first administrative actions sice taking office, as also met one of the most persistent claims of women's rights groups: that there is generally no reason for the government and others to know a woman's marital status.

The change, effective March 31, was announced about three weeks after Blumenthal received a letter from Karen DeCrow, president of the National Organization for Women (NOW), requesting an explanation of the previous practice.

Reached by telephone in Syracuse, N.Y., DeCrow said she was not surprised at the change, just "pleased." She said she did not know whether her letter had spurred the department to act.

"All ove the country there are a lot of practices that discriminate against women where people have been toying with the idea of change and if they get a little push they'll just do it," she said.

DeCrow said she had found about the practice from a person had written her to complain.

The Treasury Department has justified the mandatory use of courtesy [WORD ILLEGIBLE] on the ground that they "facilitate the identification of savings bonds claimed to be lost, stolen, or destroyed," as a press release announcing the change put it.

William M. Gregg, deputy commissioner of the public debt, explained that it is sometimes difficult to identity the beneficiary of a bond if two or more people with the same name lay claim to it. Since 1974 it has been mandatory that the owner's social security number appear on the bond but not the number of any co-owners or beneficiaries.

Gregg said the number of such cases involving identical names was few and it had been decided that is view of complaints about the practice "it wasn't that big of a problem that we should persist in it."