CAMBRIDGE, MASS. -- Twelve computer companies announced last week they were paying $150,000 apiece to support a project by Massachusetts Institute of Technology to develop a standard for computer screen displays.

The companies in the newly formed consortium include giants such as International Business Machines Corp., Digital Equipment Corp., American Telephone & Telegraph & Co., Hewlett-Packard Co., Sony Corp. and Apple Computer Inc.

The companies agreed to support MIT's new X Windows standard, which establishes a way for computers to display in "windows" on a screen several programs running at the same time.

X Windows has been under development for three years and an earlier version was introduced one year ago. The 12 companies contributed the money to improve the standard and said they would make sure their computers were capable of using it.

The existence of a single standard will make it easier for computer software developers to write programs that will run on a variety of different kinds of computers, Robert Scheifler, an MIT researcher and a chief architect of the X system, told a news conference.

Aerospace, automotive and heavy manufacturing companies using computers for design, engineering and manufacturing have become more adamant in recent years about wanting improved windowing standards, experts said.

Other founding members of the MIT X Consortium include Apollo Computer Inc.; CalComp; Sequent Computer Systems Inc.; Sun Microsystems Inc.; Tektronix Inc.; and Xerox Corp.

Companies expected to join later, according to MIT officials, include France's Bull SA and Fujitsu America Inc.