LAGOS Oct 8 (Reuters) - A former Nigerian bank chief was sentenced to 18 months in jail for fraud on Friday and ordered to hand over $1.2 billion in cash and assets, the first such sentencing to follow last year's banking sector crisis.

Cecilia Ibru, former managing director of Oceanic Bank, had pleaded guilty to three of 25 counts in a plea bargain agreed with the Economic and Financial Crimes Commission (EFCC), a spokesman for the anti-graft agency said.

"The court convicted and sentenced her on the three counts , with a forfeiture of assets and funds totalling 190 billion naira," EFCC spokesman Femi Babafemi told Reuters.

Nigeria's central bank injected $4 billion into nine lenders last year which were deemed to be dangerously undercapitalised as a result of reckless lending and lax management.

Most people in Africa's most populous nation live on $2 or less each day, but the country's tycoons are among the continent's richest. Many own private jets and have interests in a wide range of companies.

The Nigerian bank crisis was partly caused by banks lending money unsecured to companies in which executives, and in some cases their families, had interests.

Executives were charged with offences ranging from granting loans without adequate security to share price manipulation.