It also faced huge losses in personal computers and declining sales in its cash-cow mainframe line.

If I.B.M. holds to past practice, in addition to expanding its mainframe line, it can be expected in several years to begin introducing performance improvements that increase the speed of its systems.

Given the portability of CICS/6000, IBM could even have - or could still - offer CICS running over Tuxedo on its mainframe line.

I.B.M. unveiled a replacement for its antiquated mainframe line, but deliveries will not be made before late 1994.

Filip's group is also discussing with IBM's ES/9000 mainframe developers about its possible use of RISC processors in the mainframe line.

IBM reinvigorated their mainframe line with CMOS technologies, which made them among the most powerful and cost efficient in the marketplace.

Unisys reported that sales of its key mainframe lines, the A Series and the 2200 Series, posted "double-digit" gains last year.

Both mainframe lines - the A Series and 2200 Series - saw double digit growth over 1991, while Unix revenues grew at nearly double the mainframe growth rate.

The new mainframe, however, will have less than two-thirds the processing power of I.B.M.'s 3090 mainframe line and most likely would not win over many new customers, analysts said.

In its mainframe line, I.B.M. said demand exceeded supply in the second quarter, although mainframe revenue declined from last year's period as a result of price reductions.