By Sam Tabahriti and Muvija M

LONDON, Jan 7 (Reuters) - Britain's financial watchdog said on Monday it had fined two former Carillion finance directors after they dropped appeals against findings that they mislead investors about the company's financial health before it collapsed in 2018.

The Financial Conduct Authority (FCA) said that Richard Adam and Zafar Khan knew of serious problems in Carillion's UK construction arm, but failed to disclose them in market statements or alert the board or the audit committee.

Carillion, which was once one of Britain's biggest contractors with 43,000 employees, collapsed in January 2018 under 7 billion pounds ($9.45 billion) of liabilities, disrupting public services and major projects.    

Adam and Khan had been fined 232,800 pounds and 138,900 pounds, respectively, after dropping their appeals, the FCA said in a statement, less than the 318,000 pounds and 154,400 pounds penalties the regulator set out in its 2022 decision notices.

The FCA said the former finance directors acted recklessly and were "knowingly concerned" in breaches of market abuse and listing rules, including the publication of misleading information and failures to maintain adequate controls.

"Those in positions of responsibility have a duty to keep the market accurately and adequately informed," said Steve Smart, the FCA's joint executive director of enforcement.

Khan, who stepped down as Carillion's finance director after just nine months in September 2017, said in a statement he had agreed to settle because after nearly eight years he no longer had the resources to continue defending the case.

"I continue to believe I acted at all times with integrity and in the best interests of the company," said Khan, adding he had devoted his energies to tackling Carillion's challenges.

Reuters was not immediately able to contact Adam.

Former Carillion CEO Richard Howson is contesting related findings, with a tribunal hearing set for February 16, the FCA said.

Khan has been banned from holding directorships for 11 years, while Adam was banned for more than 12 years, the UK's Companies House register of disqualified directors shows.

($1 = 0.7410 pounds)

(Reporting by Muvija M and Sam Tabahriti, editing by Catarina Demony and Alexander Smith)