The Japanese automaker Nissan completed its current contract after the final match of the England tour in Bulawayo on Sunday and is not renewing, sources said.
Nissan had been supplying about 70 cars at heavy discounts for use by executives, officials, coaches and other staff.
Bata Shoe company, the biggest in Zimbabwe, withdrew all sponsorship about a month ago. It had been supplying equipment and clothing, some of it imported from Pakistan.
Managing director Edwin Duthie said the main reason was "because I could hardly spend so much money on cricket while at the same time laying off workers."
He added: "However, I did become concerned about the performance of the present Zimbabwe team. We have spent hundreds of millions of dollars on the national side over the years but I'm afraid there seems to be little hope of real improvement soon. It's a matter of credibility for us."
Simon Hamilton, chief executive of Old Mutual, a leading finance house here, said he would be having talks with Zimbabwe Cricket in the next few weeks.
"I am not able to say anything about my approach to those talks. They are necessary because our three-year contract with Zimbabwe Cricket concludes in February or March," he said.
He confirmed that Old Mutual had spent more than one million US dollars in support of Zimbabwe cricket since 2000.
The Old Mutual sponsorship relates notably to Test matches.
Zimbabwe were suspended from Test cricket after two crushing defeats at home to Sri Lanka in May, but are due to return to the five-day game in January with a series away to fellow strugglers Bangladesh.
Talks are also due soon over the sponsorship of the Zimbabwe cricket academy, the establishment and construction of which were mainly funded by a foreign exchange bureau, CFX, which has since supported it.
Manager Kevin Butler said: "Discussions about future sponsorship are on the table. Our contract is up for renewal soon." He was not prepared to say whether his attitude to renewal would be negative or positive.
The England tour was not covered for South Africa and Zimbabwe TV viewers, for the first time in years, resulting in considerable loss of income. And losses due to unplayed Tests against Australia and England are believed to have exceeded 600,000 dollars.