NEW YORK, SEPT. 14 -- Chemical New York Corp., the nation's fifth-largest bank company, said today that it will eliminate 2,100 jobs in an attempt to shore up its finances, which have been undermined by shaky loans to Latin American countries.

Chemical also said that it will take a one-time charge of $135 million because of costs associated with the job cutbacks. The writeoff will result in a $65 million loss for the company during the third quarter of 1987, Chemical's second straight quarterly loss.

Chemical Bank employes and executives said this is the first time the bank has been forced to implement a major layoff. The company said that many of the targeted jobs would be eliminated through attrition and "voluntary separations," but that a large number of direct layoffs is inevitable.

"It's a very difficult experience," said Chemical vice president Ken Herz.

Last June, Chemical followed other large banks by announcing that it was boosting its loan-loss reserves by $1.1 billion to protect against troubled Latin American loans. That one-time charge resulted in a $1.1 billion loss for the bank during the second quarter.

Analysts said that since June, nearly all the major banks have been attempting to improve their finances by cutting costs, selling subsidiaries and issuing new stock.

Chemical, however, is the first to implement sweeping job reductions.

"Some of the banks have already moved in this direction," said Fred Meinke, an analyst at E.F. Hutton & Co. Inc., referring to job freezes and early retirement programs in place at several major banks.

Meinke said that he while he does not expect major layoffs to follow at other banks, "There certainly are some banks, such as Bank of America, that could still cut back on people."

News of the job eliminations at Chemical, which will fall hardest on the company's New York offices, was delivered to employes early this morning.

Workers received a letter from Chemical's chairman, Walter V. Shipley, as well as the text of a press release issued by the company and a special edition of Chemical's inhouse newsletter.

Shipley said in a statement that the cutbacks, as well as announced plans to sell several of Chemical's subsidiary businesses "will enable Chemical to achieve significantly improved earnings performance in the years ahead."

A hiring freeze has been in effect at many Chemical divisions for months and about 500 positions have been eliminated through attrition during 1987, according to Herz. But those jobs were not included in the new cutback targets announced today.

Some Chemical employes who have been at the bank at least 15 years will be offered severance packages this week as an incentive to leave the company voluntarily. Herz insisted that while the layoff program will target specific jobs at the bank, veteran employes who turn down the severance offer will face no extra risk of being laid off.

The precise number of layoffs, as opposed to voluntary departures, will be announced later in the fall. The total of 2,100 jobs to be eliminated represents about 10 percent of Chemical's work force, excluding the 7,000 employes of its recently acquired Texas Commerce Bancshares subsidiary.

Because Texas Commerce is regarded as an exceptionally efficient organization by Chemical executives, the subsidiary will be unaffected by the restructuring announced today.

Analysts said that Chemical's announcement did not come as much of a surprise.

They said that the billions of dollars in loan-loss reserves posted by Chemical and other major banks earlier this year reduced the banks' equity-to-asset ratios to precariously low levels. (An equity-to-asset ratio is one measure of a bank's financial health.)

Since then, the analysts said, all the banks have pursued strategies aimed at boosting equity.

Three large banks -- Citicorp, Manufacturers Hanover Corp., and Bankers Trust New York Corp. -- recently announced new stock sales as a means to increase equity.

The Bankers Trust offering has been completed; the others are outstanding.

Analysts said that the stock sale alternative was less attractive to Chemical because of the glut of other bank issues already in the market and because Chemical's shares are relatively undervalued by investors. If Chemical tried a stock issue, they said, the bank would run the risk that the price of its shares might be diluted.

In addition to the job eliminations, Chemical said today that it plans to sell several subsidiary businesses, including Chemical Financial Services Corp., its Cleveland-based consumer finance subsidiary.

Chemical expects the sales to be completed in 1988 and said they should generate estimated pretax gains of at least $300 million.

Those proceeds will be used to replenish Chemical's equity, the company said.