The Irish Stock Exchange (ISEQ) has confirmed as invalid a deal in which 150,000 Datalex shares were traded yesterday before the bell.
According to a ISEQ spokesperson, the shares, which were quoted at 60 cents, were entered as having been sold for 20 cents.
The mistake was the result of the entry of inaccurate information into the log of ISEQ deals which, the spokesperon said, was rectified as soon as the market closed.
All stock-information outlets were informed as soon as the mistake was noted.
In a statement issued after the close of the ISEQ - which fell 183 points, to 4,771, - the stock exchange said Datalex did not trade all day yesterday.
Datalex, which produces travel booking software, opened this morning at 68 cents and is trading 8 cents down at 60 cents.