The quarterly reshuffle of the FTSE 100 next week will seal the humiliation of Invensys, the engineering conglomerate hit by a profits warning last month.
It has dropped out of the top 200 UK companies by market value, and looks set to be one of four companies demoted to mid-cap status.
The shake-up will solve a headache for Lord Marshall of Knightsbridge, who currently falls foul of the Higgs recommendations on corporate governance by chairing two FTSE 100 companies, Invensys and British Airways. Neither looks set to remain in the premier index, when the rejig is announced on Wednesday.
And it also resolves a problem for John Napier, the chairman of Kelda, the owner of Yorkshire Water, which is on course for one of the vacant blue-chip places. He is set to become chairman of Royal & SunAlliance, but the beleaguered insurance group is headed for demotion.
There are two trading days left before the final changes are decided, but if last night's situation prevails, Rolls-Royce is the fourth company that will be ejected.
Kelda will be joined in the FTSE 100 by newcomer Provident Financial, a consumer finance group, Cable & Wireless and the Foreign & Colonial investment trust.
The industrial giant GKN is hovering just above the threshold for demotion, while Rank, the gaming group, is an outside bet to regain its blue-chip status.
The fall from grace by Invensys is one of the most dramatic since the FTSE 100 was founded in 1984. The group has been a constituent since it was created from the merger of BTR and Siebe four years ago. In that time, it has launched waves of redundancies and sold businesses, slimming down from a global workforce of 100,000 to less than 55,000 – and losing 95 per cent of its stock market value.
Its shares have plunged 66 per cent since its Valentine's Day profits warning, which it blamed on a sales downturn.