Fidelity, among the largest shareholders in Europe's top companies, said last year it would oppose any long-term incentive plan (LTIP) that allowed bosses to cash in stock options within three years, and added that from 2015 it would vote against any plans lasting less than five years.

The global fund manager's decision came after a public outcry against high levels of executive pay at blue-chip companies during times of austerity prompted the British government to insist that bonus plans must be signed off by shareholders in order to hold companies to account, encourage longer-term decision making and improve returns.

Now nearly half of FTSE 100 <.FTSE> firms insist executives hold on to share options for a minimum of between three and five years, Dominic Rossi, Fidelity's chief investment officer for equities, said on a conference call with journalists.

That compares to 17 percent of firms at the start of 2013.

Among the companies to be "fully five-year compliant" are Anglo American, AstraZeneca and BT, Fidelity said in a statement.

"The standard three-year LTIP model, which has dominated remuneration schemes in the past, has been broken and is now in retreat," said Rossi, adding there was more to do over the next 12 months.

"We want to make sure that the majority of organisations have moved and that we get an increasing number above our minimum of five years," said Rossi on the call, held to give an update on the progress of Fidelity's campaign.

He noted that the changes "haven't come without some pain." Fidelity, which manages around 160 billion pounds in assets, voted against at least one proposal at 52 percent of AGMs so far in 2014, the first time it had voted against a majority of boards.

"This progress should only encourage all shareholders to use their new powers to the fullest extent," he added.

(Editing by Sophie Walker)

By Simon Jessop

Stocks treated in this article : BT Group plc, Anglo American plc