Former CIA agent Edwin P. Wilson contracted and paid for the shipment of 40,000 pounds of plastic explosives to Libya in 1977, the owner of a California explosives firm testifed today.

The explosives dealer, Jerome S. Brower, testified in U.S. District Court here that he met with Wilson in mid-1977 in Washington to begin the transaction and met again with Wilson in Libya in October when the shipment of explosives arrived there.

Wilson, who was convicted last month in Alexandria, Va., of exporting four handguns and an M16 rifle to Libya, faces trial here on charges of exporting explosives to Libya.

Today's pretrial hearing, before U.S. District Court Judge Ross N. Sterling, was held to determine if there is sufficient evidence of a conspiracy to allow hearsay testimony in Wilson's trial, which is scheduled to begin next month.

Wilson is to be sentenced in Alexandria on Monday.

Brower, an unindicted co-conspirator whose left hand is missing several fingers, said the explosives were paid for out of $588,000 that was deposited in his Swiss bank account. He said he had charged Wilson $13.75 a pound and that Wilson had sold the explosives to the Libyans for $20 a pound.

Brower testified that he bought the explosives, called C4 or RDX, in the summer of 1977 from three firms--one in Canada, one in New Orleans, and the third in Texas.

To disguise the shipment, the explosives were repackaged in 850 five-gallon containers. The explosives were placed at the bottom of the cans and the rest of the container was filled with commercial oil drilling mud.

The labels on the outside of the packages contained safety instructions for the explosive C4, but Brower said only the long chemical name for the explosive was used. None bore a label with the word "Explosives".

The shipping was handled through associates of a firm co-owned by Wilson called Around World Shipping and Charter Co., according to the testimony of Reginald Slocombe, president of the company and an unindicted co-conspirator. The company had offices in Washington and Houston.

Slocombe said that because the explosives could not legally be shipped from the United States, it was decided that the job should be done by some company other than Around World Shipping.

"It's stuff called C4 and it's not supposed to be shipped," Slocombe told Edison Frazier, air cargo director for Around World Shipping, in a tape played in court today.

Frazier, another unindicted co-conspirator, testified that he had been put in charge of finding a shipper and had settled on Donald R. Thresher, a Houston businessman in the freight forwarding business.

Slocombe testifed that Wilson was getting anxious for the explosives to be shipped, and that there was a problem obtaining an airplane to carry the cargo to Libya. In late September, Slocombe, Frazier, Thresher and Edward Bloom, an attorney working for Brower, flew to Miami to lease a plane to ship the cargo at a cost of about $60,000.

The plane was loaded in Houston on Oct. 2 or 3, 1977, and customs documents were falsified to get the cargo out of the country. In the middle of the night, the plane left Houston for Lisbon with Bloom aboard, Frazier said.

Brower testified that he had flown separately to Lisbon, then accompanied the cargo into Libya.

In Libya, Brower said he called Wilson to get someone to unload the cargo. Brower said his passport was lifted there and he waited for several days, at Wilson's apartment, until he was told that the explosives were all right.

At one point today, Brower described silver medallions he had given to several employes working in Libya; they were to be used for identification purposes. He said he carried one himself as a "lucky piece."

"But it didn't work, did it?" Judge Sterling said.

"In response to his honor's question, no sir," Brower replied.