IBM and Sun Microsystems yesterday intensified competition in an already crowded operating systems market with an agreement to co-operate on distributing Sun's Solaris operating software on IBM's PowerPC platform. The deal represents a big shot in the arm for Sun's software subsidiary, SunSoft, which has struggled with mixed success to sell Solaris as a platform standard. While Solaris has been successful in niche technical workstation markets, the new arrangement with IBM puts Solaris on what is expected to eventually become a mass-market platform to rival Intel's x86 environment. Specifically, the two companies - which compete ferociously in the UNIX workstation market - will co-operate in porting the Solaris operating system to the PowerPC platform, and will allow IBM to distribute Solaris on PowerPC machines under an original equipment manufacturer agreement. An IBM spokesman said the company would distribute the operating system either pre-loaded on sales of PowerPC systems, or on CD-ROM. The technical modifications to Solaris that optimise it for the PowerPC will be completed by both companies. The system will be available in the first half of next year. ''We have all along intended to have a lot of different environments available on the PowerPC platform, so this is another piece that has fallen into place,'' said Lai Yee-chong, IBM's PowerPC product manager. IBM has said its PowerPC products will run AIX applications (AIX is IBM implementation of UNIX), Windows, DOS, Macintosh and OS/2 programs. It will later include Windows NT from Microsoft, and Taligent, its joint-development project with Apple aiming to design a new operating system. To allow applications to be ported to Solaris for the PowerPC, SunSoft will - with IBM's co-operation - support programs to assist independent software and hardware vendors migrating to the platform. The programmes include technology conferences, the establishment of porting and technical support centres in various regions as well as early access to technology. SunSoft also intends to expand its existing third-party Catalyst programme to include PowerPC developers. It will make Early Access Developer Kits for Solaris on PowerPC-based personal systems available in October. SunSoft said Solaris on PowerPC-based systems from IBM would contain the same features, functionality and Application Programming Interface as Solaris 2.4, which will be available on SPARC-and x86-based systems this summer. In most cases, SunSoft said, software developers would need only a simple ''recompile'' to migrate its applications to the Solaris PowerPC platform. Meanwhile, IBM is also understood to be working on a new operating system - codenamed WorkPlace - to run applications meant for PCs, workstations and mid-range computers. Agency reports say that in the PC arena WorkPlace is intended to be compatible with every big PC platform - OS/2, DOS, Windows, Macintosh and the new PowerPC. Brent Williams, PC programming director for International Data Corp in the United States, said: ''IBM is committed to the desktop strategy because if it does not have an offering, it gives up control of its hardware business to an outside company. ''If you let Microsoft be the sole supplier of operating systems for your PCs then it has the opportunity to innovate its software in such a way to make you innovate your hardware in a certain way. ''You don't want to let somebody else have that control.'' With a PC, the firm controlling the operating system dictates the software that goes into it.