LONDON (Reuters) - Shire, the $47 billion (£33.1 billion) rare disease drugmaker being stalked by Japan's Takeda Pharmaceutical, faces fresh criticism over its executive pay policy from a leading investor advisory group as a crunch week approaches.

Shareholders will vote on pay and other matters at Shire's annual general meeting on April 24, a day before Takeda must decide whether it will make a takeover bid. Shire will then report first-quarter results on April 26.

Pensions & Investment Research Consultants (PIRC), which advises pension funds and others how to vote at AGMs, believes that Shire CEO Flemming Ornskov's maximum potential bonus is "excessive" at 780 percent of salary, even though he took a pay cut last year.

Ornskov's total remuneration last year fell to $5.3 million, from $10.6 million in 2016, after a disappointing year for the company, which is registered in Jersey, headquartered in Dublin and listed in London.

Shire faces increased competition both from generic and new drugs made by rivals, prompting Ornskov in January to ditch a previous revenue target of $20 billion by 2020.

Two years ago almost half of its shareholders voted against Shire's executive pay plans during a spate of criticism of pay packages at a number of companies. The Shire remuneration report then won 93 percent support in 2017.

Two other shareholder advisory groups, ISS and Glass Lewis, said they recommended votes in favour of all of Shire's 2018 AGM proposals, including the CEO's pay.

A Shire spokesman declined to comment.

Ornskov has come under fire from investors after his $32 billion purchase of Baxalta in 2016, which exposed Shire to increased risk in the haemophilia market at a time when a new drug from Roche and pending gene therapies threatened disruption.

The widely criticised Baxalta deal marked a change in sentiment towards Shire, a former stock market darling that was nearly bought by AbbVie in 2014, with the U.S. suitor walking away because of changes to U.S. tax rules.

Two days ago Shire agreed to sell its cancer drugs business to France's Servier for $2.4 billion. The move highlighted value in its portfolio but may also have frustrated Takeda, which cited oncology as one factor behind its interest.

Shire started life in 1986 as a tiny business selling calcium supplements from above a shop in southern England but has evolved into a global drugmaker, driven by deal-making and some big bets on high-priced speciality medicines.

(Editing by David Goodman)

By Ben Hirschler

Stocks treated in this article : Takeda Pharmaceutical Co Ltd, Roche Holding Ltd., Shire, AbbVie