The First National Bank of Chicago has been designated as the first middleman for joint ventures between the China International Trust and Investment Corp. and businesses around the world.

The agreement, announced Monday by First Chicago Chairman A. Robert Abboud and China International head Rong Yiren, makes the bank the screening agent for all proposals by foreign businesses to set up projects with the People's Republic of China. First Chicago has also been given responsibility to solicit business ventures for the Chinese.

The agreement gives the Chinese an insight into Western business they had not had previously.

The agreement was signed as officials from the China Investment Corp. made their first official visit to the United States. The corporaton began operations officially on Oct. 4 after enactment of a law covering joint ventures in that nation by the Chinese state council last summer.

The 15-point act includes guidelines for such ventures, including tax breaks for foreign corporations.

First Chicago was the first U.S. bank to establish a full correspondence banking relationship with the PRC.The new agreement strengthens that relationship.

The agreement came less than a week before hearings on the most favored nation treaty designation for China by the trade committee of Rep. Al Ullman's (D-Ore.) House Ways and Means Committee. Those hearings are scheduled for Thursday and Friday.