The Bank of England stepped up its support for the UK bond market, aiming to prevent a rout in a $1 trillion part used by the pensions industry from spreading.

The move is designed to bring an orderly finish to emergency purchases at the end of this week and to provide longer-term support for a wider range of securities in the coming weeks.

The measures may give a boost to corporate credit, which has seen demand plummet along with other sterling-denominated assets since the Prime Minister Liz Truss's government set out a series of tax cuts that spooked investors.

"The measure itself will be positive near term," said Bob Stoutjesdijk, a fund manager at Robeco Institutional Asset Management.

UK bonds were initially steady after the announcement, before edging lower. The 30-year yield was six basis points higher at 4.45% at 8:55 a.m. London. It surged past 5% for the first time since 2002 after investors took fright at the prospect of higher supply and higher interest rates following the new government's mini budget last month.

The measures stem from the BOE's concerns that pension funds following so-called liability-driven investment strategies, or LDIs, were under pressure to liquidate £50 billion of long-term bonds in the last week of September, four times the usual daily average.

The BOE said it will: Together, the measures are aimed at ensuring that the LDI funds that need to unwind positions have the liquidity in the market to act by the end of this week. They also provide a broader assurance that the BOE stands ready to keep the market working even as investors make a dramatic shift in their valuation of a wide range of UK assets.

So far, investors haven't taken up as much of the support as the BOE has offered. In the eight auctions to date, the BOE bought just £4.6 billion of bonds, about 12% of the £40 billion capacity of the program.

Monday's move also raises questions whether the BOE will be able to move ahead with separate plans to start selling off some of the assets it built up over the past decade under the Quantitative Easing program.