THE Monetary Authority stepped in to help banks yesterday with $14 billion in loans after some ''had difficulty'' in keeping their liquidity positions. An unprecedented statement from the Monetary Authority said banks had been forced to tap $14 billion from the liquidity adjustment facility, the last resort of banks in Hong Kong that legally must maintain a minimum cash, or near-cash instrument, ratio to total assets of not less than 25 per cent. The problems came during the funding of a Dao Heng share subscription yesterday. The Dao Heng spin-off by Guoco Group involved a $834 million flotation of 14.38 million new Dao Heng shares and 14.14 million Guoco shares offered to the public at $21.70 each. Market sources said last night that the floatation had been ''well over'' 200 times oversubscribed. As cheques were cleared at Standard Chartered Bank, the receiving bank for the issue, short-term Hong Kong dollar interest rates shot up. In the morning session they rose from Monday's close of 4.375 per cent to 4.5 per cent, despite a $1 billion injection by the Monetary Authority into the interbank market. The price of short-term money continued to rise and at one point overnight rates leapt to more than six per cent but closed at 3.5 per cent to four per cent, below the offer rate at which the liquidity adjustment facility lends. The price of money was still higher than it has been since the floatation of Denway Investment in February when rates soared to 7.5 per cent and the fore-runner of the Monetary Authority decided to introduce tougher rules on share offers. The authority issued a statement last night saying it had lent more than $14 billion to banks short of money during the course of the day through the liquidity adjustment facility and had in turn taken $18 billion from banks with a surplus late in the day. Stanley Wong, treasurer at Standard Chartered in Hong Kong, said the first injection of $1 billion into the market had left the facility with a negative balance of about $4 billion. ''Late in the day, someone, or more likely a batch of people, put $4 billion back leaving a balance of $4 million in the facility. The facility gives the Authority the ability to act as lender of last resort for banks with a liquidity position which breaks Hong Kong's strict rules on cash at hand for banks. The authority blamed the past week's series of big share issues for the problems. ''Interbank liquidity has been tight, mainly because of heavy investor interest in new share issues,'' a spokesman said. New issues including China play Kunming Machine Tool, retailer Esprit and Dao Heng have all proved popular with investors. Kunming's issue of 65 million shares at $1.98 was 627 times oversubscribed, close to Denway's record of 657 times. The last big peak on the interbank market came when Manhattan Card and Wing Hang Bank listed on the same day. Manhattan Card was 40 times oversubscribed when it issued 388 million shares at $1.87 on July 2. On the same day, Wing Hang went to the market 109 times oversubscribed when it raised $619 million through a 38.85 million share offer at $16.80 a share. On that day, the interbank rate closed the day at four per cent.