Rational has $500 million in net cash, which works out to about $2 a share.

Average net cash in the year to September stood at £240m, compared with its £1.7bn market capitalisation.

For example, in 2000, Enron said its net cash provided by operations totaled $4.8 billion.

Also the company has net cash of around £2.5m, and so enjoys extra income with higher interest rates.

The company has net cash of $137m, to be used for drilling and development next year, but sources said management wants to do more exploration.

The group had average net cash over the period of £224m.

This will boost our estimated net cash of £210m for 2012 by around 43% to £300m.

The practice is believed to increase net cash provided by operating activities.

The transaction (which included a couple other assets) cost C$15 million in net cash.

There are opportunities in Japan to buy profitable companies at little more than the net cash on their balance sheets.