Yen’s appointment as executive vice president of Sun’s storage group was announced in May. According to sources, senior executives were told at that time that in October Yen would be taking up a lecturing post, possibly at Stanford University in California.

But Sun has insisted that none of this is true, and that Yen has no plans to leave his post, or take a sabbatical. The rumors about David Yen leaving are false, the company said.

One possibility is that Yen will not be taking a sabbatical, but will be lecturing part-time while he continues in his role as Sun storage chief.

Even in ordinary circumstances the appointment of an executive at this level with only a few months service possible would be an unusual move. It would even more surprising in this case, because Sun is in the middle of a merger with Storage Technology Corp, which it bought last year for around $3bn cash – a $4.1bn purchase price less StorageTek’s $1bn reserves.