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                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
 
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                                   FORM 10-K
                             ---------------------
                                 ANNUAL REPORT
                     PURSUANT TO SECTION 13 OR 15(d) OF THE
                        SECURITIES EXCHANGE ACT OF 1934
 
                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1998
 
                        COMMISSION FILE NUMBER 333-15789
 
                                 CHEMFIRST INC.
             (Exact name of Registrant as specified in its charter)
 
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                 MISSISSIPPI                                     64-0679456
       (State or other jurisdiction of                        (I.R.S. Employer
        incorporation or organization)                      Identification No.)
 
       700 NORTH STREET, P. O. BOX 1249
             JACKSON, MISSISSIPPI                                39215-1249
   (Address of principal executive offices)                      (Zip Code)
</TABLE>
 
       Registrant's telephone number, including area code: (601) 948-7550
 
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  Securities registered pursuant to Section 12(b) of the Act:
 
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             TITLE OF EACH CLASS                  NAME OF EACH EXCHANGE ON WHICH REGISTERED
             -------------------                  -----------------------------------------
<S>                                             <C>
         Common Stock, Par Value $1                        New York Stock Exchange
        Common Stock, Purchase Rights
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     Indicate by check mark whether the Registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.     YES  [X]     NO  [ ]
 
     Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of Registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K.     [X]
 
     The aggregate market value of the voting stock held by non-affiliates of
the Registrant as of March 18, 1999 (based on the closing sale price of $21.5625
of the Registrant's Common Stock, as reported on the New York Stock Exchange
Composite Tape on such date) was approximately $367,698,585.
 
     The number of shares of the Registrant's Common Stock outstanding as of
March 18, 1999 is 18,360,735.
 
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                      DOCUMENTS INCORPORATED BY REFERENCE
 
     Certain information required to be disclosed in this Form 10-K is
incorporated by reference to the Company's 1998 Annual Report to Stockholders
and the Company's definitive Proxy Statement for the May 25, 1999 annual meeting
of stockholders. The location of the incorporated information is as follows:
 
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                 PART I OF FORM 10-K                             LOCATION IN ANNUAL REPORT
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<S>       <C>                                             <C>
Item 1.   Business......................................  Notes 2 and 12 in Financial Review Insert

                 PART II OF FORM 10-K
                 --------------------
Item 5.   Market for Registrant's Common Equity and
          Related Stockholder Matters...................  p. 12
Item 6.   Selected Financial Data.......................  p. 2
Item 7.   Management's Discussion and Analysis of
          Financial Condition and Results of
          Operations....................................  Financial Review Insert
Item 7A.  Quantitative and Qualitative Disclosures about
          Market Risk...................................  See Management's Discussion and Analysis
                                                          of Financial Condition and Results of
                                                          Operations in Financial Review Insert
Item 8.   Financial Statements and Supplementary Data...  Financial Review Insert

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                                                                    LOCATION IN DEFINITIVE
                 PART III OF FORM 10-K                                 PROXY STATEMENT
                 ---------------------                              ----------------------
<S>       <C>                                             <C>
Item 10.  Directors and Executive Officers of the
          Registrant....................................  pp. 4-7; 10-12
Item 11.  Executive Compensation........................  pp. 10; 11; 13-21
Item 12.  Security Ownership of Certain Beneficial
          Owners and Management.........................  pp. 2; 3; 8-10
Item 13.  Certain Relationships and Related
          Transactions..................................  p. 17
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                                     PART I
 
ITEM 1. BUSINESS
 
GENERAL
 
     The principal businesses of ChemFirst Inc. (the "Company") involve the
production of electronic and other specialty chemicals for use in the
semiconductor industry and in agricultural, pharmaceutical, polymer,
photographic and photosensitive applications, as well as the production of
polyurethane chemicals. The Company has reclassified the engineered products and
services operation and the steel operation as discontinued operations pending
disposition of these businesses. It is anticipated that the disposition of the
engineered products and service business will take place during 1999. The
Company also plans to divest the steel business in 1999, although adverse
industry conditions have hampered this effort.
 
     At March 1, 1999, the Company had 1,087 employees, which includes employees
of the parent company and all subsidiaries.
 
  Recent History
 
     The Company was incorporated in Mississippi in 1983 under the name Omnirad,
Inc., as a wholly-owned subsidiary of First Mississippi Corporation ("First
Mississippi"). In November 1996, in anticipation of the Distribution (as defined
below), the Company's name was changed from Omnirad, Inc. to ChemFirst Inc. On
December 23, 1996 (the "Distribution Date"), First Mississippi contributed all
of its assets and subsidiaries, other than those relating to its fertilizer
business, to the Company, which at that time was a wholly owned subsidiary of
First Mississippi and had engaged in no activities during the previous five
years. First Mississippi then spun off the Company in a tax-free distribution of
the Company's common stock to First Mississippi shareholders (the
"Distribution") on the Distribution Date. The Distribution occurred immediately
prior to and in connection with the merger of First Mississippi with a wholly
owned subsidiary of Mississippi Chemical Corporation on December 24, 1996,
pursuant to an Agreement and Plan of Merger and Reorganization dated as of
August 27, 1996. The Company has operated as a publicly held entity since the
Distribution Date. Prior to the Distribution Date, the Company's subsidiaries
were subsidiaries of First Mississippi and the Company's operations were
conducted through subsidiaries of First Mississippi.
 
  Recent Developments
 
     On December 31, 1997, the Company acquired the acylation derivatives
business of Clariant Corporation. This business is conducted through TriQuest,
L.P., a limited partnership in which the Company owns an 87.5% interest, with
the remaining 12.5% interest owned by former members of Clariant Corporation's
acylation derivatives management group who are also employees of TriQuest. This
acylation derivatives business is involved in the development and marketing of
derivatives of 4-hydroxyacetophenone for deep ultraviolet ("DUV") photoresist
resin applications for advanced integrated circuits with line geometries of 0.25
microns and below and for polymer additives and specialty adhesives. Also on
December 31, 1997, the Company acquired certain chemical mechanical
planarization ("CMP") assets of Baikowski International Corporation, a
subsidiary of Baikowski Chimie, SA, and the CMP assets of Moyco Technologies,
Inc. and its affiliate, Sweet Pea Technologies, Inc. The acquisition of these
CMP assets provided the Company with an entrance into the CMP market, which
includes mechanical polishing of silicon wafers utilizing a slurry of abrasives
and chemicals to produce a flatter surface for shorter wavelength lithography.
Acylation derivatives and CMP are included in the Company's Electronic and Other
Specialty Chemicals segment.
 
     On January 22, 1998, the Company sold its 50% interest in Power Sources,
Inc. ("PSI") to Trigen Energy Corporation ("Trigen") for approximately $20.0
million. As of January 21, 1999, there are contingencies specified in the
purchase and sale agreement with Trigen that could result in the Company
refunding as much as $750,000 of the proceeds referenced above, and accordingly,
the Company has classified these proceeds as deferred revenue pending resolution
of the contingencies. The Company no longer has an ownership interest in PSI.
The Company's disposition of its interests in PSI and the planned disposition of
the
 
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engineered products and services business and the steel business is in
furtherance of the Company's strategy to focus on chemicals.
 
  Forward-Looking Statements
 
     In addition to historical information, this Form 10-K contains
"forward-looking statements" within the meaning of the Private Securities
Litigation Reform Act of 1995. Such forward-looking statements, as well as other
forward-looking statements made from time to time by the Company in the
Company's press releases, Annual Report to Stockholders and other filings with
the U.S. Securities and Exchange Commission, are based on certain underlying
assumptions and expectations of management. These forward-looking statements are
subject to risks and uncertainties which could cause actual results to differ
materially from those expressed in such forward-looking statements. Such risks
and uncertainties include, but are not limited to, general economic conditions,
availability and pricing of raw materials, supply/demand balance for key
products, new product development, manufacturing efficiencies, product demand by
key customers, the timely completion and start-up of construction projects, the
timing and completion of the Company's anticipated sale of the engineered
products and services business and the disposition of the steel business,
pricing pressure as a result of the continued downturn in Asian and other
international markets, successful installation of the new company-wide
Enterprise Resource Planning system to integrate the Company's information
systems, the inability of the Company to either resolve the Company's Year 2000
issues or to accurately estimate the costs associated with Year 2000 compliance,
the resolution of contingencies related to the sale of Power Sources, Inc.,
insurance coverage related to hurricane damage to the Company's Pascagoula
facility and other factors as may be discussed herein.
 
     The following contains further discussion of the Company's business and
properties as grouped by its Electronic and Other Specialty Chemicals segment
and its Polyurethane Chemicals segment. Financial information regarding the
Company's segments, which includes sales, pretax operating results and
identifiable assets, is provided in Note 12 of the Consolidated Financial
Statements, incorporated by reference. Also discussed below is information
regarding the Company's engineered products and services business and steel
business which are reported as discontinued operations in anticipation of the
disposition of these operations. As used in this report, the term "Company"
includes subsidiaries of the registrant.
 
ELECTRONIC AND OTHER SPECIALTY CHEMICALS
 
  General
 
     The Company's Electronic and Other Specialty Chemicals segment produces
specialty chemicals for use by others in electronic, agricultural,
pharmaceutical, polymer and photosensitive applications. These chemicals are
typically produced by multi-step batch processing. These products are sold both
on specification and performance and must typically be qualified for use by the
customer in addition to meeting certain specifications. The chemicals in this
segment are sold in smaller volumes and have a higher value added component than
those associated with the polyurethane chemicals. Another commonality of the
chemicals sold in this segment is the Company's focus on applied research.
Whereas the primary focus for many of the Company's customers in this segment is
on basic discovery, much of the Company's focus is on development of products
and processes for our customers' next generation semiconductors, pharmaceutical,
agricultural or consumer products. These chemicals are produced at facilities in
Hayward, California, East Kilbride, Scotland, Pascagoula, Mississippi, Tyrone,
Pennsylvania and Dayton, Ohio.
 
     Purchasers of electronic chemicals, who are typically end-users, acquire
the product to achieve a specific performance objective. As with the other
specialty chemicals, these chemicals have very specific uses, although the
customer base is often larger than for other specialty chemicals. The production
and sale of these chemicals are labor intensive and are usually dependent on
highly technical proprietary formulae and a sophisticated, well-trained
applications engineering staff. The Company's electronic chemicals are used in
the semiconductor and related industries. These chemicals include organic
post-metal cleaning solutions which remove photoresist and dry-etch residue
during the manufacture of semiconductors, post-dry-etch polymer removers, deep
ultraviolet resins for production of photoresists, and other performance
chemicals and
 
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materials for cleaning and polishing silicon wafers in semiconductor
manufacturing. The Company's electronic and other specialty chemicals accounted
for approximately 59%, 60% and 61% of the Company's consolidated sales for 1998,
1997 and 1996, respectively.
 
     Most of the Company's other specialty chemicals are sold to a narrow base
of customers, which are either end-users or producers of performance chemicals.
Because of their specialized, complex molecular structure, these products are
designed for specific end-use for one or two customers and significant technical
service is expected by the customer. The key to successful production of these
specialty chemicals is identifying the markets for the product and developing a
chemical synthesis production route and process. These chemicals are sold as
intermediates to other specialty chemical producers and to agricultural,
electronic, pharmaceutical, polymer and cosmetics companies for use in
herbicides, a plant growth regulator, plastic curatives, cosmetics, protease
inhibitors, rubber processing chemicals, optical brighteners, dyestuffs and
pigments, and photoinitiators. The Company makes substantial sales of a
herbicide ingredient to one manufacturer under an agreement that will expire in
2002.
 
     The Company owns and operates electronic chemical manufacturing facilities
in Hayward, California and East Kilbride, Scotland. The Company's 65,000 square
foot California facility includes offices, research and development labs and
manufacturing and packaging facilities. The California facility currently
utilizes approximately 70% of production capability on a one-shift, five-day
basis. During 1998, the Company completed an expansion and improvement project
at its 26,300 square-foot Scotland facility. The Scotland facility currently
utilizes approximately 80% of available production capability on a one-shift,
five-day basis. Utilization is expected to drop to about 40% within several
months when full capacity and expected operating efficiencies from the 1998
expansion are brought fully online. Thus, the Company has substantial capacity
to expand production. The Company leases office and applications engineering lab
space in Kawasaki City, Japan to provide marketing and technical support for the
Japanese electronic chemical markets, and also leases an applications laboratory
in Phoenix, Arizona for the development of CMP products.
 
     The Company produces specialty chemicals manufactured to the specifications
and performance criteria of its customers ranging from gram to commercial
manufacturing quantities. These multifunctional manufacturing facilities enable
the Company to perform multi-step batch and continuous processing of specialties
and custom production of complex fine chemicals. The Company has versatile
facilities that use numerous reactors capable of producing custom fine chemicals
in quantities ranging from the very small amounts needed for initial product
testing, through pilot plant production of developmental quantities and
continuing through commercial production. Although historically customers have
purchased relatively small quantities of certain specialty chemicals, primarily
for their new product development and market testing, recently the sale of
commercial quantities of product has increased significantly as the trend to
outsource strengthens. Companies involved in the mass production of chemically
based agricultural, pharmaceutical and consumer products often find it expensive
and inefficient to manufacture small quantities of the complex chemicals
required for new product development or products with limited markets. By
providing a versatile array of manufacturing capabilities, related services and
capacity to a number of such companies, the Company achieves economies of scale
and is able to manufacture certain fine specialty chemicals more economically
and timely than they can be manufactured by its customers. As a result,
customers can reduce the time to market and capital exposure associated with the
manufacture and marketing of their new developmental products and are able to
better utilize and focus their own manufacturing capacity and research and
development abilities.
 
     The Company produces specialty and electronic chemicals at Tyrone,
Pennsylvania, Dayton, Ohio and Pascagoula, Mississippi. All of these facilities
are owned by the Company. Annual production capacity at the Tyrone facility is
between 4.5 million and 6.0 million pounds, depending on the product mix and the
type of processing required. Production in 1998 was approximately 6.0 million
pounds. During 1998, the Company completed an expansion at the Dayton facility
for the production of DUV photoresist resins. The Dayton facility also includes
a cGMP (current Good Manufacturing Practices) pilot plant for scale-up work and
production of small quantities of fine and pharmaceutical chemicals. Annual
production capacity at Dayton is between 1.5 million and 2.0 million pounds
depending on the product mix and the type of processing required. Production in
1998 was approximately 1.0 million pounds. Specialty chemical production
capacity at Pascagoula is between 70 million and 80 million pounds, depending on
the product mix and the processing
 
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required. Production at this facility was approximately 61 million pounds during
1998. At these sites, the Company has differentiated itself by its capacity to
manufacture electronic and/or other specialty chemicals using multi-step batch
processing combined with the capability to produce specialty chemicals through
continuous process technology. In addition, the Company outsources the
manufacture of selected small volume chemicals.
 
  Marketing and Sales
 
     Electronic chemicals are marketed domestically and internationally in
Europe and the Pacific Rim. The California facility serves North America and the
Pacific Rim, and the Scotland facility serves the European community. These
chemicals are distributed in gallon, liter, returnable drum or large volume
dedicated containers. In Japan, the Company's electronic chemicals are
repackaged from bulk containers into returnable containers by the Company's
Japanese distributor. In late 1998, the Japanese distributor began toll
manufacturing select Company products for distribution in Japan. A majority of
the Company's electronic chemicals are sold through its internal sales force
although the Company utilizes independent sales representatives as well.
 
     The Company's other specialty chemicals are marketed globally. Most of
these chemicals are sold by purchase order or short-term agreements although the
Company has long-term contracts with a number of its largest customers. A
significant amount of these chemical sales are to three customers under
long-term contracts. These chemicals sales are made primarily through the
Company's internal sales force. Most of these specialty chemicals are sold in
drums. Exported product is shipped in ocean-going tankers, iso-containers or
drums to European, Japanese and South American markets. Domestic shipments are
typically by truck.
 
  Raw Materials
 
     The primary raw materials for the manufacture of electronic chemicals
include free-base hydroxylamine, diglycolamine, N-methylpyrrolidone and alumina
powders. With the exception of hydroxylamine, raw materials are generally
available in adequate quantities from several suppliers, subject to market
variation in price. Hydroxylamine is currently available from one supplier,
located in Japan. The Company is seeking an additional source of hydroxylamine
and is currently evaluating samples supplied by another manufacturer. The supply
of 4-hydroxyacetophenone, a primary raw material for the Company's acylation
derivatives business, is available from a single source under a long-term
contract.
 
     Primary raw materials for the production of its other specialty chemicals
include hydrogen, hydrogen peroxide, caustic, toluene, ethyl
trifluoroacetoacetate, 2-Fluorophenylhydrazine, o-aminophenol, formaldehyde,
ethanol and natural gas. These raw materials are obtained from a number of
different sources. The Company does not believe that any one source for raw
materials used in the production of these chemicals is material to the Company's
business.
 
  Competition
 
     The Company is one of the largest producers of post-metal cleaning
solutions for semiconductor production. Although there are approximately 12
companies participating in this market worldwide, only the Company and three
others have significant market share for advanced and post-metal cleaning
solutions required by the current state of the art semiconductor and related
industries. Competition is based on service, product performance, quality,
product development capabilities and cost of ownership. The Company has entered
into a cross-licensing agreement with a major competitor whereby the Company
licenses its HDA(TM) (hydroxylamine) patented etch residue remover technology.
The agreement results from a patent infringement complaint brought by the
Company against the competitor in federal court. The agreement allows the
competitor to continue to market its products which utilize the Company's
hydroxylamine technology, but provides for the Company to receive a royalty and
license fee. The Company has approximately five U.S. and four foreign patents
regarding its HDA(TM) technology. The earliest of these patents expires in 2011.
Regarding CMP, the oxide slurry market is dominated by two other companies, with
the larger company holding a 90%
 
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market share. In the tungsten slurry market, the Company is now the third
largest supplier for this application. The Company is one of the largest
suppliers of products to the global DUV photoresist resin market.
 
     The Company competes domestically and internationally with numerous
producers of specialty chemicals. Major competitors are both smaller and larger
companies. Competition is fierce and is based on service, quality, manufacturing
capabilities and expertise in batch chemical production, research and
development capabilities and price. The Company's large batch manufacturing
sites allow it the flexibility and breadth of service to meet a wide variety of
customer needs, including the ability to provide gram and multi-ton quantities
in either cGMP (current Good Manufacturing Practices) or ISO-9000 manufacturing
environments.
 
  Seasonality of Business
 
     Generally, electronic and other specialty chemical sales are not seasonal
and working capital requirements do not vary significantly from period to
period.
 
POLYURETHANE CHEMICALS
 
  General
 
     The Company produces aniline and nitrobenzene by a continuous production
process at its facilities in Pascagoula, Mississippi and Baytown, Texas. Unlike
electronic and other specialty chemicals, these chemicals generally require
additional processing steps and chemical reactions to produce the end product
used by consumers and are primarily sold under long-term contracts.
 
     Typically, polyurethane chemicals are more sensitive to the business cycle
and the cost of raw materials than are most electronic and specialty chemicals,
although the Company's sales contracts provide protection from fluctuation in
raw material price for most of the aniline sold. These chemicals are typically
sold in large volumes to industrial customers that purchase on the basis of
product specifications. The key to successful production of these chemicals is
efficient chemical conversion of large quantities of raw materials and
productive use of plant capacity. Providing technical services to customers is
generally less important than for specialty products.
 
     The Company's manufacturing facility in Pascagoula is supported by storage,
rail, truck, barge and ship distribution facilities. The Pascagoula facility
utilizes nitration technology and a proprietary process for continuous
hydrogenation. The annual polyurethane chemical production capacity at the
facility is between 315 million and 350 million pounds depending on the products
being produced. Production of polyurethane chemicals at the Pascagoula facility
during 1998 was approximately 335 million pounds, which was lower than planned
because of production problems during the first half of the year and a hurricane
during the third quarter.
 
     In 1996, the Company entered into a long-term agreement with Bayer
Corporation ("Bayer") to build, own and operate a world scale nitrobenzene and
aniline facility at Bayer's Baytown, Texas chemical complex to supply Bayer's
MDI (methylene diphenyl diisocyantate) manufacturing operations. Phase I of the
facility, with a design capacity of 250 million pounds, was completed in 1998
and is now operating near design capacity. If a potential Phase II to the
facility is constructed, it would add another 250 million pounds of capacity. A
majority of the Company's current aniline production from the Pascagoula
facility is sold to Bayer under a long-term contract. If Phase II of the Baytown
facility is constructed, Bayer may terminate this contract and take requirements
from the Baytown facility.
 
     Aniline is the Company's largest volume product. The Company is among the
largest merchant marketers of aniline in the U.S. Most of the aniline produced
in the U.S. is used to manufacture MDI. MDI's primary end-use is in rigid
polyurethane foam, an insulation material that is widely used in residential and
commercial construction. MDI is also used in the manufacture of impact-resistant
plastic that is used as a replacement for metal in automobile parts such as
bumpers, where flexibility and impact resistance are important. Aniline's other
primary applications are in the production of an antioxidizing (anti-cracking)
agent used in the manufacture of synthetic rubber and in a widely used herbicide
for corn and soybeans.
 
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Polyurethane chemicals accounted for approximately 41%, 40% and 39% of the
Company's consolidated sales for 1998, 1997 and 1996, respectively.
 
     Nitrobenzene is used to make aniline and is also sold separately for the
manufacture of pharmaceuticals, rubber and agricultural chemicals.
 
  Marketing and Sales
 
     The Company's polyurethane chemicals are sold primarily in the U.S. Most
chemicals produced in this segment are sold under long-term contracts to a
number of customers. The Company's internal sales force accounts for essentially
all of the sales in this segment. These products are generally sold in bulk.
Domestic shipments are by barge, rail or tank trucks and exports are shipped in
ocean-going tankers, iso-containers or drums.
 
  Raw Materials
 
     Benzene, which is a principal raw material for polyurethane chemicals
production, is a readily available commodity by-product of oil refining. Like
most commodities, the price of benzene is subject to fluctuation. Benzene prices
are affected by the demand for a variety of products, principally including
styrene and phenolic resins. The Company is protected from fluctuations in raw
material prices under the contracts in which most of its aniline production is
sold. The remainder of its production is sold under short-term contracts or
purchase orders at prices that generally reflect its actual raw material cost.
Other significant raw materials include ammonia and natural gas. The Company
purchases ammonia at market prices. The Company purchases natural gas in the
spot market for use in producing the hydrogen necessary for its manufacturing
processes. This gas is transported into the Pascagoula plant through an
interstate pipeline. Prices paid by the Company for natural gas are affected by
the degree of interruptibility of the gas supply.
 
  Competition
 
     The Company is one of five major U.S. producers of aniline, with
approximately 25% of domestic capacity and an estimated 7.5% of world capacity.
Major competitors are large chemical companies. Competition for the products
produced in this segment is based on price, service, quality, marketing and
research and development support capabilities.
 
  Seasonality of Business
 
     Generally, the Company's polyurethane chemical sales are not seasonal and
working capital requirements do not vary significantly from period to period.
 
COMPANY RESEARCH AND DEVELOPMENT
 
     The Company conducts research and development to improve existing products,
to develop and produce new specialty and performance chemicals and to develop
and improve production processes. The Company spent approximately $10.7 million,
$5.3 million and $5.8 million on research and development in 1998, 1997 and
1996, respectively. Research facilities include laboratories, pilot plant and
semi-works for process research and development with gram to multi-pound sample
production capabilities. The Company maintains a radiation curing applications
laboratory in Pascagoula to evaluate new products and provide customer technical
support. The Company's electronic chemicals applications engineering and
research and development labs in California, Texas, Scotland and Japan are
strategically located near key regional semiconductor production centers,
enabling applications engineers to work closely with customers to develop unique
chemical solutions to semiconductor manufacturing needs and to test
developmental products. The Company continues to focus research efforts on
developing new and improved electronic chemicals, including remover products,
CMP and DUV resins. The Company also sponsors applied research at leading
universities in the U.S. and the U.K. These closely directed programs have led
to the development and introduction of proprietary technology in electronic and
other specialty chemicals. In addition, the Company has entered into a joint
development
 
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arrangement with an industry consortium to develop advanced products to meet
future semiconductor manufacturing technology.
 
COMPANY PATENTS
 
     The Company owns, or is licensed under, a number of patents, patent
applications and trade secrets covering its products and processes. The Company
believes that, in the aggregate, the rights under such patents and licenses are
important to its operations, but, with the exception of the HDA(TM) etch residue
remover patents referenced above, does not consider any patent, or license, or
group thereof related to a specific process or product, to be of material
importance when viewed from the standpoint of the Company's total business.
 
ENVIRONMENTAL CONSIDERATIONS
 
     Company operations are subject to a wide variety of environmental laws and
regulations governing emissions to the air, discharges to water sources, and the
handling, storage, treatment and disposal of waste materials, as well as other
laws and regulations concerning health and safety conditions. The Company holds
a number of environmental permits and licenses regulating air emissions, water
discharges and hazardous waste disposal and, to the best of its knowledge, is in
material compliance with such requirements at all locations. The Company makes
capital and other expenditures in a continuing effort to comply with
environmental laws and regulations, or changing interpretations of existing laws
and regulations. The Company's environmental capital expenditures for 1998 were
$0.2 million. Projected environmental capital expenditures for 1999 and 2000 are
$1.4 million and $1.1 million, respectively. While these expenditures are
necessary to comply with environmental laws and regulations, they may also
reduce operating expenses and improve efficiencies.
 
     The Company monitors and participates in the environmental regulatory
development process which assists it in evaluating new laws and regulations. The
Company does not anticipate a material increase in expenses related to current
environmental regulations, but because federal and state environmental laws and
regulations are constantly changing, the Company is unable to predict their
future impact.
 
     The Company has received notices from the U.S. Environmental Protection
Agency or similar state agencies that it has been deemed a potentially
responsible party ("PRP") under Superfund or a comparable state statute at
several sites and, thus, may be liable for a share of the associated remediation
cost. It is difficult to estimate the Company's ultimate liability relating to
these sites due to several uncertainties such as, but not limited to, the method
and extent of remediation, the percentage of material attributable to the
Company at the site relative to that attributable to other parties, and the
financial capabilities of the other PRPs. Based on currently available
information, however, the Company does not believe that its future liability at
these sites will be material to its financial condition, results of operations,
cash flow or competitive position.
 
DISCONTINUED OPERATIONS
 
     Following is a brief discussion of the Engineered Products and Services
business and the Steel business, both of which are reported as discontinued
operations in anticipation of being divested.
 
ENGINEERED PRODUCTS AND SERVICES
 
     The Company has announced plans to dispose of the Engineered Products and
Services business and it has been classified as a discontinued operation. The
Company anticipates that the disposition should be completed during 1999. This
business principally includes the development and marketing of proprietary
equipment and systems for industrial applications. These include design and
production of low-emission burners, flares, incinerators and thermal plasma
equipment. Raw materials and components for these operations are available from
numerous vendors. The businesses are not considered materially seasonal. This
business is operated primarily through the Company's subsidiary Callidus
Technologies Inc.
 
     Principal products and services are custom designed and fabricated
gas/liquid incinerators, flares, solid waste systems, vapor recovery units,
burners and thermal plasma heating systems. The Company also provides
engineering and consulting services for environmental and combustion
applications.
 
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     The Company markets these products and services worldwide to refining,
petrochemical, chemical, pharmaceutical, wood products and other industries
requiring disposal of gas, liquid and solid wastes. Marketing is primarily
through a combination of manufacturers' representatives and company personnel.
The market is well established but growing through advancements of existing
technology, driven primarily by increasingly strict environmental regulations
both in the U.S. and abroad. Competition is based on a wide variety of factors,
with the most prominent being price, technological innovation and delivery
schedule. The Company competes with the John Zink Company, which has a
significant share of the burner, flare and vapor recovery markets. Numerous
competitors exist in the gas and liquids incineration market. Primary
competition in the solid waste systems market comes from alternative
technologies. The Company is affected by a variety of factors beyond its
control, including governmental control of environmental standards and
compliance deadlines, competitor pricing strategies and changing technology; any
one of which could impact operating results. The Company leases office space in
Tulsa, Oklahoma, owns a manufacturing and test facility in Beggs, Oklahoma and
has leased foreign offices in Belgium, England, France, Germany and Japan.
 
STEEL
 
     The Company's Steel business is operated through its subsidiary, FirstMiss
Steel, Inc. This operation is conducted through a 400,000 square-foot steel
melting and production facility in Hollsopple, Pennsylvania, which is
approximately 100 miles east of Pittsburgh. As previously noted, the Company
plans to divest the steel business. These efforts have been hampered by adverse
industry conditions. The Company leases the land on which the facility is
located but has the right to purchase the land for a nominal price at the
conclusion of the lease. Annual capacity of the operation includes 150,000 tons
of carbon, alloy and specialty grade, bottom-poured ingots and 50,000 tons of
high-grade steel billets through a horizontal continuous caster. The value-
added product line includes specialty stainless and tool steel ingots or
billets, which are converted into forged billets, bars and plates by outside
processors. Small quantities of cobalt, nickel, copper and iron-based alloys in
bars and wire are also produced from two small horizontal continuous casters,
small bottom-poured forging ingots and remelt sand ingots. There is an adequate
supply in the North American market of steel scrap and various alloys for raw
material use.
 
     Carbon and alloy steel ingots are sold directly to the forging industry,
ring rollers, extruders and integrated steel producers. The Company competes
primarily with three other steel companies in this market. Specialty steel
products are primarily sold to steel service centers and forgers. Ten customers
account for approximately 60% of the Company's steel revenue. Alloy products are
sold as feedstock directly to forgers, extruders and investment casters. There
are numerous competitors, both domestic and foreign, that compete with the
Company in the specialty steel, ferrous and nonferrous metals markets.
Competitive factors include price, quality and service. Carbon steel ingots and
billets are commodities and are extremely price competitive. Stainless and tool
steel long product pricing is currently being pressured by strong import
penetration.
 
ITEM 2. PROPERTIES
 
     A description of various properties and the segments to which they relate
is included in the Business discussion located on pages 4 through 10 of this
Form 10-K. In addition to those described above, the Company owns or leases the
following properties:
 
     The Company owns an approximately 26,000 square-foot office building in
Jackson, Mississippi, which is its corporate headquarters.
 
     The Company leases 7 acres of waterfront property from the Jackson County
Port Authority. This property is used for loading and unloading ocean-going
vessels and barges at its Pascagoula, Mississippi facility. The lease expires in
2003.
 
     The Company owns 70 acres of undeveloped industrial land within 2 miles of
the Pascagoula plant and 23 acres directly adjacent to the Pascagoula plant. The
Company also owns approximately 78 acres of undeveloped industrial land directly
adjacent to its Tyrone, Pennsylvania facility.
 
                                       10
<PAGE>   11
 
     The Company leases research and development laboratory space in Corpus
Christi, Texas to support its acylation derivatives business.
 
     The Company is a party to a long-term lease agreement covering 24,356
square-feet of office space in Jackson, Mississippi. The Company has entered
into an agreement with a real estate management firm to assist the Company in
subleasing this space.
 
     The Company believes that its properties are suitable and adequate for the
purposes for which they are used.
 
ITEM 3. LEGAL PROCEEDINGS
 
     The Company has pending several claims incurred in the normal course of
business which, in the opinion of management and legal counsel, can be disposed
of without material effect on the Company's financial statements.
 
ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
 
     No matters were submitted to a vote of security holders of the Company,
through the solicitation of proxies or otherwise, during the fourth quarter of
1998.
 
                                    PART II
 
ITEMS 5-8. MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER
           MATTERS, SELECTED FINANCIAL DATA, MANAGEMENT'S DISCUSSION AND
           ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS,
           QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK, AND
           FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA
 
     The information called for by Part II, Items 5-8, has been included in the
Registrant's Annual Report to Stockholders for the fiscal year ended December
31, 1998 (or the Financial Review insert attached thereto), which has been
furnished to the Commission and portions of which are incorporated herein by
reference. See "Documents Incorporated by Reference" on Page 2 hereof for the
locations of such information.
 
ITEM 9. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND 
        FINANCIAL DISCLOSURE
 
     Not applicable.
 
                                    PART III
 
ITEMS 10-13. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT, EXECUTIVE
             COMPENSATION, SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND
             MANAGEMENT, AND CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
 
     The information called for by Part III, Items 10-13, has been included in
the Registrant's definitive Proxy Statement for the May 25, 1999 Annual Meeting
of Stockholders, which will be filed with the Commission by March 30, 1999,
pursuant to Regulation 14A, and is incorporated herein by reference. See
"Documents Incorporated by Reference" on Page 2 hereof for the location of such
information.
 
                                       11
<PAGE>   12
 
                                    PART IV
 
ITEM 14. EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K
 
FINANCIAL STATEMENTS AND SCHEDULES
 
     (a)(1) Financial Statements Incorporated by Reference to the Financial
Review insert which is attached to the Registrant's Annual Report to
Stockholders for the fiscal year ended December 31, 1998 and Supplementary Data.
 
<TABLE>
<CAPTION>
                                                                       PAGES IN
                                                                   FINANCIAL REVIEW
                                                                  INSERT TO THE 1998
                                                                     ANNUAL REPORT
                                                                    TO STOCKHOLDERS
                                                                  INCORPORATED HEREIN
                                                                     BY REFERENCE
                                                                  -------------------
    <S>                                                           <C>
    Consolidated Balance Sheets as of December 31, 1998 and
      1997......................................................  p. 6
    Consolidated Statements of Operations, years ended December
      31, 1998, 1997 and 1996...................................  p. 7
    Consolidated Statements of Stockholders' Equity, years ended
      December 31, 1998, 1997 and 1996..........................  p. 8
    Consolidated Statements of Cash Flows, years ended December
      31, 1998, 1997 and 1996...................................  p. 9
    Notes to Consolidated Financial Statements..................  p. 10-28
    Independent Auditors' Report................................  p. 28
</TABLE>
 
     (a)(2) Additional schedules are either not required under the applicable
instructions or are inapplicable and have therefore been omitted.
 
     (a)(3) EXHIBITS
 
<TABLE>
<CAPTION>
        EXHIBIT
         NUMBER                                  DESCRIPTION
        -------                                  -----------
<C>                      <S>
            2(a)         Agreement and Plan of Merger and Reorganization, dated as of
                         August 27, 1996, among Mississippi Chemical Corporation,
                         MISS SUB, INC. and First Mississippi Corporation, was filed
                         as Exhibit 2.1 to Amendment No. 1 to the Company's Form S-1
                         (Registration No. 333-15789) filed on November 18, 1996, and
                         is incorporated herein by reference.
            2(b)         Agreement and Plan of Distribution between First Mississippi
                         Corporation and the Company dated December 18, 1996 was
                         filed as Exhibit 2.2, Form of Agreement and Plan of
                         Distribution, to Amendment No. 1 to the Company's Form S-1
                         (Registration No. 333-15789) filed on November 18, 1996, and
                         is incorporated herein by reference. The only modification
                         to the text of the Form of Agreement and Plan of
                         Distribution which is incorporated herein by reference was
                         the substitution of "ChemFirst Inc." for "Newco" as a party
                         to this agreement and the dating of the agreement as of
                         December 18, 1996.
            2(c)         Tax Disaffiliation Agreement between First Mississippi
                         Corporation and the Company dated December 18, 1996 was
                         filed as Exhibit 2.3, Form of Tax Disaffiliation Agreement,
                         to Amendment No. 1 to the Company's Form S-1 (Registration
                         No. 333-15789) filed on November 18, 1996, and is
                         incorporated herein by reference. The only modification to
                         the text of the Form of Tax Disaffiliation Agreement which
                         is incorporated herein by reference was the substitution of
                         "ChemFirst Inc." for "Newco" as a party to this Agreement
                         and the dating of the agreement as of December 18, 1996.
</TABLE>
 
                                       12
<PAGE>   13
 
<TABLE>
<CAPTION>
        EXHIBIT
         NUMBER                                  DESCRIPTION
        -------                                  -----------
<C>                      <S>
            2(d)         Employee Benefits and Compensation Agreement between First
                         Mississippi Corporation and the Company dated December 18,
                         1996 was filed as Exhibit 2.4, Form of Employee Benefits and
                         Compensation Agreement, to Amendment No. 1 to the Company's
                         Form S-1 (Registration No. 333-15789) filed on November 18,
                         1996, and is incorporated herein by reference. The only
                         modification to the text of the Form of Employee Benefits
                         and Compensation Agreement which is incorporated herein by
                         reference was the substitution of "ChemFirst Inc." for
                         "Newco" as a party to this Agreement and the dating of the
                         agreement as of December 18, 1996.
            3(a)         Amended and Restated Articles of Incorporation of the
                         Company were filed as Exhibit 3.1 to Amendment No. 1 to the
                         Company's Form S-1 (Registration No. 333-15789) filed on
                         November 18, 1996, and is incorporated herein by reference.
            3(b)         Bylaws of the Company as amended were filed as Exhibit 4.3
                         to the Company's Form S-8 (Registration No. 333-69965) filed
                         on December 30, 1998, and is incorporated herein by
                         reference.
            4(a)         Articles III, IV, V, VI, VII, VIII, IX and X of the
                         Company's Charter of Incorporation and the Statements of
                         Resolution establishing the Company's 1987-A, 1988-A,
                         1988-1, 1989-A, 1989-1, 1989-2, 1990-1, 1990-2, 1991-1,
                         1991-2, and 1992-1 Series Convertible Preferred Stock and
                         the Company's Series X Junior Participating Preferred Stock
                         are included in Exhibit 3(a).
            4(b)         Articles II, IV, IX and XII of the Company's Bylaws are
                         included in Exhibit 3(b).
            4(c)         ChemFirst Inc. 401(K) Savings Plan was filed as Exhibit 4.4
                         to the Company's Registration Statement on Form S-8
                         (Registration No. 333-18691) filed on December 24, 1996 and
                         is incorporated herein by reference.
            4(d)         Rights Agreement, dated as of October 30, 1996, between the
                         Company and KeyCorp Shareholder Services, Inc., was filed as
                         Exhibit 4 to Amendment No. 1 to the Company's Form S-1
                         (Registration No. 333-15789) filed on November 18, 1996 and
                         is incorporated herein by reference.
            4(e)         First Amendment to Rights Agreement dated effective May 1,
                         1997, by and among the Company, KeyCorp Shareholders
                         Services, Inc. and The Bank of New York, was filed as
                         Exhibit 4.5 to the Company's Form S-8 (File No. 333-69965)
                         filed on December 30, 1998, and is incorporated herein by
                         reference.
            4(f)         Post Spin-Off Agreement between First Mississippi
                         Corporation and FirstMiss Gold Inc. dated as of September
                         24, 1995, which was assigned to the Company in connection
                         with the Distribution, was filed as Exhibit 99.1 to First
                         Mississippi's Form 8-K dated September 24, 1995, and is
                         incorporated herein by reference.
            4(g)         Tax Ruling Agreement between First Mississippi Corporation
                         and FirstMiss Gold Inc. dated as of September 24, 1995,
                         which was assigned to the Company in connection with the
                         Distribution, was filed as Exhibit 99.2 to First
                         Mississippi's Form 8-K dated September 24, 1995, and is
                         incorporated herein by reference.
            4(h)         Loan Agreement between First Mississippi Corporation and
                         FirstMiss Gold Inc., dated as of September 24, 1995, which
                         was assigned to the Company in connection with the
                         Distribution, was filed as Exhibit 99.3 to First
                         Mississippi's Form 8-K dated September 24, 1995, and is
                         incorporated herein by reference.
            4(i)         Amended Tax Sharing Agreement between First Mississippi
                         Corporation and FirstMiss Gold Inc. dated as of September
                         24, 1995, which was assigned to the Company in connection
                         with the Distribution, was filed as Exhibit 99.4 to First
                         Mississippi's Form 8-K dated September 24, 1995, and is
                         incorporated herein by reference.
</TABLE>
 
                                       13
<PAGE>   14
 
<TABLE>
<CAPTION>
        EXHIBIT
         NUMBER                                  DESCRIPTION
        -------                                  -----------
<C>                      <S>
            4(j)         Note Purchase Agreement between ChemFirst Inc., State Farm
                         Life Insurance Company and Nationwide Life Insurance Company
                         dated October 15, 1998.
           10(a)*        Termination Agreement, dated May 29, 1996 and effective June
                         1, 1996, and amended March 15, 1999 between the Company and
                         its Chief Executive Officer.
           10(b)*        Form of Termination Agreement, dated May 29, 1996 and
                         effective June 1, 1996, between the Company and each of the
                         following executive officers of the Company: Daniel P.
                         Anderson, Robert P. Barker, William P. Bartlett, Max P.
                         Bowman, Troy B. Browning, J. Steven Chustz, Paul J. Coder,
                         William B. Kemp, Scott A. Martin, James L. McArthur, George
                         M. Simmons, R. Michael Summerford and Thomas G. Tepas, which
                         was assigned to the Company in connection with the
                         Distribution, was filed as Exhibit 10(d) to First
                         Mississippi's Annual Report on Form 10-K for the fiscal year
                         ended June 30, 1996, and is incorporated herein by
                         reference. (Company's Termination Agreement with its
                         executive officers contains terms substantially identical to
                         those contained in the form of Agreement filed.)
           10(c)*        ChemFirst Inc. 1980 Long-Term Incentive Plan was filed as
                         Exhibit 4.6 to the Company's Registration Statement on Form
                         S-8 (Registration No. 333-18693) filed on December 24, 1996,
                         and is incorporated herein by reference.
           10(d)*        ChemFirst Inc. 1988 Long-Term Incentive Plan was filed as
                         Exhibit 4.5 to the Company's Registration Statement on Form
                         S-8 (Registration No. 333-18693) filed on December 24, 1996,
                         and is incorporated herein by reference.
           10(e)*        ChemFirst Inc. 1995 Long-Term Incentive Plan was filed as
                         Exhibit 4.4 to the Company's Registration Statement on Form
                         S-8 (Registration No. 333-18693) filed on December 24, 1996,
                         and is incorporated herein by reference.
           10(f)*        ChemFirst Inc. 1998 Long-Term Incentive Plan was included as
                         Appendix A to the Company's Proxy Statement filed in
                         connection with the Annual Meeting of Stockholders held on
                         May 27, 1998, and is incorporated herein by reference.
           10(g)*        1991 Restatement of the First Mississippi Directors'
                         Retirement Plan, as revised and restated on May 14, 1991,
                         which was assigned to and assumed by the Company pursuant to
                         the Benefits Agreement, was filed as Exhibit 10(f) to First
                         Mississippi's Annual Report on Form 10-K for the fiscal year
                         ended June 30, 1991, and is incorporated herein by
                         reference.
           10(h)*        First Mississippi Corporation 1989 Deferred Compensation
                         Plan for Outside Directors, as amended on September 12,
                         1994, which was assigned to and assumed by the Company
                         pursuant to the Benefits Agreement, was filed as Exhibit
                         10(g) to First Mississippi's Annual Report on Form 10-K for
                         the fiscal year ended June 30, 1995, and is incorporated
                         herein by reference.
           10(i)*        A description of the Company's Deferred Income Plan for
                         Directors, Officers and Key Employees ("Plan A") is included
                         in the Company's Proxy Statement filed in connection with
                         the Annual Meeting of Stockholders to be held on May 25,
                         1999, and is incorporated herein by reference.
</TABLE>
 
                                       14
<PAGE>   15
 
<TABLE>
<CAPTION>
        EXHIBIT
         NUMBER                                  DESCRIPTION
        -------                                  -----------
<C>                      <S>
           10(j)*        Form of Indemnification Agreement between the Company and
                         the following Directors or Officers of the Company, which
                         was assigned to and assumed by the Company in connection
                         with the Distribution, (Company's Indemnification Agreements
                         with each such individual contains substantially identical
                         provisions to those contained in the form): Richard P.
                         Anderson, Paul A. Becker, James W. Crook, James E. Fligg,
                         Charles R. Gibson, Robert P. Guyton, Charles P. Moreton,
                         Paul W. Murrill, William A. Percy, II, Maurice T. Reed, Jr.,
                         Frank G. Smith, Leland R. Speed, R. Gerald Turner, J. Kelley
                         Williams, R. Michael Summerford, O. E. Wall, Charles M.
                         McAuley, J. Steve Chustz, James L. McArthur, Danny P.
                         Anderson and Thomas G. Tepas was filed as Exhibit 10(t) to
                         First Mississippi's Annual Report on Form 10-K for the
                         fiscal year ended June 30, 1988, and is incorporated herein
                         by reference.
           10(k)         ChemFirst Inc. 1997 Employee Stock Purchase Plan was filed
                         as Exhibit 4.3 to the Company's Registration Statement on
                         Form S-8 (Registration No. 333-35221) filed on September 9,
                         1997, and is incorporated herein by reference.
           13            ChemFirst Inc. 1998 Annual Report to Stockholders and
                         Financial Review insert attached thereto (such Annual Report
                         is not, except for those portions thereof which are
                         expressly incorporated by reference, to be deemed "filed" as
                         part of this Form 10-K).
           21            List of the subsidiaries of the Company.
           23            Consent regarding incorporation of auditor's report into
                         Registration Statement Nos. 333-18691, 333-18693, 333-35221,
                         and 333-69965.
           27            Financial Data Schedule.
</TABLE>
 
---------------
 
 *  Indicates management contract or compensatory plan or arrangement.
 
     Certain debt instruments have not been filed. The Company agrees to furnish
a copy of such agreement(s) to the Commission upon request.
 
     (b) No Reports on Form 8-K were filed by the Company during the fourth
quarter of 1998.
 
     (c) Please see (a)(3) above.
 
     The exhibits filed with the Commission are not included in the printed copy
of the Form 10-K. A copy of the exhibits will be provided upon payment of a
reasonable fee, to be specified at the time a request is made.
 
     (d) Please see (a)(2) above.
 
                                       15
<PAGE>   16
 
                                   SIGNATURES
 
     Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.
 
                                            CHEMFIRST INC.
 
                                            By:   /s/ J. KELLEY WILLIAMS
                                              ----------------------------------
                                                     J. Kelley Williams,
                                                   Chief Executive Officer
 
Date: March 25, 1999
 
     Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
Registrant and in the capacities and on the dates indicated.
 
<TABLE>
<CAPTION>
                      SIGNATURE                                     TITLE                    DATE
                      ---------                                     -----                    ----
<C>                                                    <S>                              <C>
 
               /s/ J. KELLEY WILLIAMS                  Chairman of the Board of         March 25, 1999
-----------------------------------------------------    Directors, Chief Executive
                 J. Kelley Williams                      Officer (Principal Executive
                                                         Officer) and Director
 
                /s/ R. M. SUMMERFORD                   President and Chief Operating    March 25, 1999
-----------------------------------------------------    Officer
                  R. M. Summerford
 
                  /s/ MAX P. BOWMAN                    Vice President, Finance and      March 25, 1999
-----------------------------------------------------    Treasurer (Principal
                    Max P. Bowman                        Financial Officer)
 
                /s/ TROY B. BROWNING                   Controller (Principal            March 25, 1999
-----------------------------------------------------    Accounting Officer)
                  Troy B. Browning
 
               /s/ RICHARD P. ANDERSON                           Director               March 25, 1999
-----------------------------------------------------
                 Richard P. Anderson
 
                 /s/ PAUL A. BECKER                              Director               March 25, 1999
-----------------------------------------------------
                   Paul A. Becker
 
                 /s/ JAMES W. CROOK                              Director               March 25, 1999
-----------------------------------------------------
                   James W. Crook
 
                /s/ MICHAEL J. FERRIS                            Director               March 25, 1999
-----------------------------------------------------
                  Michael J. Ferris
 
                 /s/ JAMES E. FLIGG                              Director               March 25, 1999
-----------------------------------------------------
                   James E. Fligg
 
                /s/ ROBERT P. GUYTON                             Director               March 25, 1999
-----------------------------------------------------
                  Robert P. Guyton
</TABLE>
 
                                       16
<PAGE>   17
 
<TABLE>
<CAPTION>
                      SIGNATURE                                     TITLE                    DATE
                      ---------                                     -----                    ----
<C>                                                    <S>                              <C>
                 /s/ PAUL W. MURRILL                                Director            March 25, 1999
-----------------------------------------------------
                   Paul W. Murrill
 
              /s/ WILLIAM A. PERCY, II                              Director            March 25, 1999
-----------------------------------------------------
                William A. Percy, II
 
                  /s/ DAN F. SMITH                                  Director            March 25, 1999
-----------------------------------------------------
                    Dan F. Smith
 
                 /s/ LELAND R. SPEED                                Director            March 25, 1999
-----------------------------------------------------
                   Leland R. Speed
 
                /s/ R. GERALD TURNER                                Director            March 25, 1999
-----------------------------------------------------
                  R. Gerald Turner
</TABLE>
 
                                       17
<PAGE>   18
 
                               INDEX TO EXHIBITS
 
<TABLE>
<CAPTION>
        EXHIBIT
         NUMBER                                    DESCRIPTION
        -------                                    -----------
<C>                        <S>
 
            4(j)           -- Note Purchase Agreement between ChemFirst Inc., State
                              Farm Life Insurance Company and Nationwide Life Insurance
                              Company dated October 15, 1998.
           10(a)           -- Termination Agreement, dated May 29, 1996 and effective
                              June 1, 1996, and amended March 15, 1999 between the
                              Company and its Chief Executive Officer.
           13              -- ChemFirst Inc. 1998 Annual Report to Stockholders and
                              Financial Review insert attached thereto (such Annual
                              Report is not, except for those portions thereof which
                              are expressly incorporated by reference, to be deemed
                              "filed" as part of this Form 10-K).
           21              -- List of the subsidiaries of the Registrant.
           23              -- Consent regarding incorporation of auditor's report into
                              Registration Statement Nos. 333-18691, 333-18693,
                              333-35221 and 333-69965.
           27              -- Financial Data Schedule [For EDGAR filing only].
</TABLE>
 
---------------
 
(Note: The exhibits filed with the Commission are not included in this copy of
       the Form 10-K. A copy of the exhibits will be provided upon payment of a
       reasonable fee, to be specified at the time a request is made.)