The National Press Building Corp. has signed an agreement designed to help independent and foreign broadcasters transmit television news better.

The contract allows Pyramid Video Inc., which operates out of the press building, to put satellite transmission equipment on top of the building. This will enable Pyramid to send and receive television programming via an earth station in suburban Virginia, bypassing an American Telephone & Telegraph system that sends much of the programming through New York. Press Building tenants will continue to have access to the AT&T system, as well.

Pyramid President Jackson H. Polk said at a press conference Monday that during peak periods -- such as right after the assassination attempt on President Reagan or during the inauguration -- the AT&T circuits get jammed and the independent networks and foreign broadcasters can have problems getting their transmissions through.

Polk said the service, which is to be available in about 30 days, will be similar to that now provided by AT&T and that the cost will be roughly the same.

Any organization can subscribe to the service but precedence will be given to National Press Club tenants, Polk said.

D. Randy Allen of Pyramid said the company is working with the Pennsylvania Avenue Development Corp. to make sure the equipment on top of the press building is not offensive.