International Totalizator Systems, the Carlsbad-based manufacturer of...

International Totalizator Systems, the Carlsbad-based manufacturer of race-track wagering systems and lottery ticketing systems, has signed the largest contract of its history, a $20.3-million deal to supply a betting system for the Macao Jockey Club in the Portuguese colony in China.

The deal with contractor Goyoung Information Services of Taiwan follows a $6.3-million contract ITS signed last month with Goyoung. Deliveries will commence in June and proceed over the following six quarters through 1990. ITS reported a loss of $2.8 million on fiscal 1988 sales of $21.1 million.

ITS spokesman Steve Margolis said the company will increase its payroll of 192 employees 10% to 15% to help produce the new system, which will consist of 3,000 terminals both on and off the race-track site. The system also includes a mainframe computer and software.

The contract exceeds in size the $18-million contract ITS signed four years ago to supply a similar system to the Royal Hong Kong Jockey Club, Margolis said. ITS was the only bidder on the Macao contract, he said. ITS has also installed lottery and race-track betting systems in Australia and Malaysia.

In over-the-counter trading, ITS stock closed Monday up $.12, at $2.79 a share.